diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DocBook/media-entities.tmpl | 1 | ||||
| -rw-r--r-- | Documentation/DocBook/v4l/media-ioc-setup-link.xml | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/v4l/pixfmt-y12.xml | 79 | ||||
| -rw-r--r-- | Documentation/DocBook/v4l/pixfmt.xml | 1 | ||||
| -rw-r--r-- | Documentation/DocBook/v4l/subdev-formats.xml | 59 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 15 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 20 | ||||
| -rw-r--r-- | Documentation/flexible-arrays.txt | 4 | ||||
| -rw-r--r-- | Documentation/hwmon/adm1021 | 36 | ||||
| -rw-r--r-- | Documentation/hwmon/lm90 | 29 | ||||
| -rw-r--r-- | Documentation/hwmon/max16064 | 62 | ||||
| -rw-r--r-- | Documentation/hwmon/max34440 | 79 | ||||
| -rw-r--r-- | Documentation/hwmon/max8688 | 69 | ||||
| -rw-r--r-- | Documentation/hwmon/pmbus | 34 | ||||
| -rw-r--r-- | Documentation/hwmon/smm665 | 8 | ||||
| -rw-r--r-- | Documentation/hwmon/submitting-patches | 109 | ||||
| -rw-r--r-- | Documentation/input/event-codes.txt | 262 | ||||
| -rw-r--r-- | Documentation/md.txt | 10 | ||||
| -rw-r--r-- | Documentation/sound/alsa/ALSA-Configuration.txt | 7 | ||||
| -rw-r--r-- | Documentation/video4linux/sh_mobile_ceu_camera.txt | 6 | ||||
| -rw-r--r-- | Documentation/workqueue.txt | 40 |
21 files changed, 848 insertions, 84 deletions
diff --git a/Documentation/DocBook/media-entities.tmpl b/Documentation/DocBook/media-entities.tmpl index 5d259c632cdf..fea63b45471a 100644 --- a/Documentation/DocBook/media-entities.tmpl +++ b/Documentation/DocBook/media-entities.tmpl @@ -294,6 +294,7 @@ <!ENTITY sub-srggb10 SYSTEM "v4l/pixfmt-srggb10.xml"> <!ENTITY sub-srggb8 SYSTEM "v4l/pixfmt-srggb8.xml"> <!ENTITY sub-y10 SYSTEM "v4l/pixfmt-y10.xml"> +<!ENTITY sub-y12 SYSTEM "v4l/pixfmt-y12.xml"> <!ENTITY sub-pixfmt SYSTEM "v4l/pixfmt.xml"> <!ENTITY sub-cropcap SYSTEM "v4l/vidioc-cropcap.xml"> <!ENTITY sub-dbg-g-register SYSTEM "v4l/vidioc-dbg-g-register.xml"> diff --git a/Documentation/DocBook/v4l/media-ioc-setup-link.xml b/Documentation/DocBook/v4l/media-ioc-setup-link.xml index 2331e76ded17..cec97af4dab4 100644 --- a/Documentation/DocBook/v4l/media-ioc-setup-link.xml +++ b/Documentation/DocBook/v4l/media-ioc-setup-link.xml @@ -34,7 +34,7 @@ <varlistentry> <term><parameter>request</parameter></term> <listitem> - <para>MEDIA_IOC_ENUM_LINKS</para> + <para>MEDIA_IOC_SETUP_LINK</para> </listitem> </varlistentry> <varlistentry> diff --git a/Documentation/DocBook/v4l/pixfmt-y12.xml b/Documentation/DocBook/v4l/pixfmt-y12.xml new file mode 100644 index 000000000000..ff417b858cc9 --- /dev/null +++ b/Documentation/DocBook/v4l/pixfmt-y12.xml @@ -0,0 +1,79 @@ +<refentry id="V4L2-PIX-FMT-Y12"> + <refmeta> + <refentrytitle>V4L2_PIX_FMT_Y12 ('Y12 ')</refentrytitle> + &manvol; + </refmeta> + <refnamediv> + <refname><constant>V4L2_PIX_FMT_Y12</constant></refname> + <refpurpose>Grey-scale image</refpurpose> + </refnamediv> + <refsect1> + <title>Description</title> + + <para>This is a grey-scale image with a depth of 12 bits per pixel. Pixels +are stored in 16-bit words with unused high bits padded with 0. The least +significant byte is stored at lower memory addresses (little-endian).</para> + + <example> + <title><constant>V4L2_PIX_FMT_Y12</constant> 4 × 4 +pixel image</title> + + <formalpara> + <title>Byte Order.</title> + <para>Each cell is one byte. + <informaltable frame="none"> + <tgroup cols="9" align="center"> + <colspec align="left" colwidth="2*" /> + <tbody valign="top"> + <row> + <entry>start + 0:</entry> + <entry>Y'<subscript>00low</subscript></entry> + <entry>Y'<subscript>00high</subscript></entry> + <entry>Y'<subscript>01low</subscript></entry> + <entry>Y'<subscript>01high</subscript></entry> + <entry>Y'<subscript>02low</subscript></entry> + <entry>Y'<subscript>02high</subscript></entry> + <entry>Y'<subscript>03low</subscript></entry> + <entry>Y'<subscript>03high</subscript></entry> + </row> + <row> + <entry>start + 8:</entry> + <entry>Y'<subscript>10low</subscript></entry> + <entry>Y'<subscript>10high</subscript></entry> + <entry>Y'<subscript>11low</subscript></entry> + <entry>Y'<subscript>11high</subscript></entry> + <entry>Y'<subscript>12low</subscript></entry> + <entry>Y'<subscript>12high</subscript></entry> + <entry>Y'<subscript>13low</subscript></entry> + <entry>Y'<subscript>13high</subscript></entry> + </row> + <row> + <entry>start + 16:</entry> + <entry>Y'<subscript>20low</subscript></entry> + <entry>Y'<subscript>20high</subscript></entry> + <entry>Y'<subscript>21low</subscript></entry> + <entry>Y'<subscript>21high</subscript></entry> + <entry>Y'<subscript>22low</subscript></entry> + <entry>Y'<subscript>22high</subscript></entry> + <entry>Y'<subscript>23low</subscript></entry> + <entry>Y'<subscript>23high</subscript></entry> + </row> + <row> + <entry>start + 24:</entry> + <entry>Y'<subscript>30low</subscript></entry> + <entry>Y'<subscript>30high</subscript></entry> + <entry>Y'<subscript>31low</subscript></entry> + <entry>Y'<subscript>31high</subscript></entry> + <entry>Y'<subscript>32low</subscript></entry> + <entry>Y'<subscript>32high</subscript></entry> + <entry>Y'<subscript>33low</subscript></entry> + <entry>Y'<subscript>33high</subscript></entry> + </row> + </tbody> + </tgroup> + </informaltable> + </para> + </formalpara> + </example> + </refsect1> +</refentry> diff --git a/Documentation/DocBook/v4l/pixfmt.xml b/Documentation/DocBook/v4l/pixfmt.xml index c6fdcbbd1b41..40af4beb48b9 100644 --- a/Documentation/DocBook/v4l/pixfmt.xml +++ b/Documentation/DocBook/v4l/pixfmt.xml @@ -696,6 +696,7 @@ information.</para> &sub-packed-yuv; &sub-grey; &sub-y10; + &sub-y12; &sub-y16; &sub-yuyv; &sub-uyvy; diff --git a/Documentation/DocBook/v4l/subdev-formats.xml b/Documentation/DocBook/v4l/subdev-formats.xml index 7041127d6dfc..d7ccd25edcc1 100644 --- a/Documentation/DocBook/v4l/subdev-formats.xml +++ b/Documentation/DocBook/v4l/subdev-formats.xml @@ -456,6 +456,23 @@ <entry>b<subscript>1</subscript></entry> <entry>b<subscript>0</subscript></entry> </row> + <row id="V4L2-MBUS-FMT-SGBRG8-1X8"> + <entry>V4L2_MBUS_FMT_SGBRG8_1X8</entry> + <entry>0x3013</entry> + <entry></entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>g<subscript>7</subscript></entry> + <entry>g<subscript>6</subscript></entry> + <entry>g<subscript>5</subscript></entry> + <entry>g<subscript>4</subscript></entry> + <entry>g<subscript>3</subscript></entry> + <entry>g<subscript>2</subscript></entry> + <entry>g<subscript>1</subscript></entry> + <entry>g<subscript>0</subscript></entry> + </row> <row id="V4L2-MBUS-FMT-SGRBG8-1X8"> <entry>V4L2_MBUS_FMT_SGRBG8_1X8</entry> <entry>0x3002</entry> @@ -473,6 +490,23 @@ <entry>g<subscript>1</subscript></entry> <entry>g<subscript>0</subscript></entry> </row> + <row id="V4L2-MBUS-FMT-SRGGB8-1X8"> + <entry>V4L2_MBUS_FMT_SRGGB8_1X8</entry> + <entry>0x3014</entry> + <entry></entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>r<subscript>7</subscript></entry> + <entry>r<subscript>6</subscript></entry> + <entry>r<subscript>5</subscript></entry> + <entry>r<subscript>4</subscript></entry> + <entry>r<subscript>3</subscript></entry> + <entry>r<subscript>2</subscript></entry> + <entry>r<subscript>1</subscript></entry> + <entry>r<subscript>0</subscript></entry> + </row> <row id="V4L2-MBUS-FMT-SBGGR10-DPCM8-1X8"> <entry>V4L2_MBUS_FMT_SBGGR10_DPCM8_1X8</entry> <entry>0x300b</entry> @@ -2159,6 +2193,31 @@ <entry>u<subscript>1</subscript></entry> <entry>u<subscript>0</subscript></entry> </row> + <row id="V4L2-MBUS-FMT-Y12-1X12"> + <entry>V4L2_MBUS_FMT_Y12_1X12</entry> + <entry>0x2013</entry> + <entry></entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>y<subscript>11</subscript></entry> + <entry>y<subscript>10</subscript></entry> + <entry>y<subscript>9</subscript></entry> + <entry>y<subscript>8</subscript></entry> + <entry>y<subscript>7</subscript></entry> + <entry>y<subscript>6</subscript></entry> + <entry>y<subscript>5</subscript></entry> + <entry>y<subscript>4</subscript></entry> + <entry>y<subscript>3</subscript></entry> + <entry>y<subscript>2</subscript></entry> + <entry>y<subscript>1</subscript></entry> + <entry>y<subscript>0</subscript></entry> + </row> <row id="V4L2-MBUS-FMT-UYVY8-1X16"> <entry>V4L2_MBUS_FMT_UYVY8_1X16</entry> <entry>0x200f</entry> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index b6ed61c95856..7c163477fcd8 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -52,8 +52,10 @@ Brief summary of control files. tasks # attach a task(thread) and show list of threads cgroup.procs # show list of processes cgroup.event_control # an interface for event_fd() - memory.usage_in_bytes # show current memory(RSS+Cache) usage. - memory.memsw.usage_in_bytes # show current memory+Swap usage + memory.usage_in_bytes # show current res_counter usage for memory + (See 5.5 for details) + memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap + (See 5.5 for details) memory.limit_in_bytes # set/show limit of memory usage memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage memory.failcnt # show the number of memory usage hits limits @@ -453,6 +455,15 @@ memory under it will be reclaimed. You can reset failcnt by writing 0 to failcnt file. # echo 0 > .../memory.failcnt +5.5 usage_in_bytes + +For efficiency, as other kernel components, memory cgroup uses some optimization +to avoid unnecessary cacheline false sharing. usage_in_bytes is affected by the +method and doesn't show 'exact' value of memory(and swap) usage, it's an fuzz +value for efficient access. (Of course, when necessary, it's synchronized.) +If you want to know more exact memory usage, you should use RSS+CACHE(+SWAP) +value in memory.stat(see 5.2). + 6. Hierarchy support The memory controller supports a deep hierarchy and hierarchical accounting. diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 274b32d12532..492e81df2968 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -387,26 +387,6 @@ Who: Tejun Heo <tj@kernel.org> ---------------------------- -What: Support for lcd_switch and display_get in asus-laptop driver -When: March 2010 -Why: These two features use non-standard interfaces. There are the - only features that really need multiple path to guess what's - the right method name on a specific laptop. - - Removing them will allow to remove a lot of code an significantly - clean the drivers. - - This will affect the backlight code which won't be able to know - if the backlight is on or off. The platform display file will also be - write only (like the one in eeepc-laptop). - - This should'nt affect a lot of user because they usually know - when their display is on or off. - -Who: Corentin Chary <corentin.chary@gmail.com> - ----------------------------- - What: sysfs-class-rfkill state file When: Feb 2014 Files: net/rfkill/core.c diff --git a/Documentation/flexible-arrays.txt b/Documentation/flexible-arrays.txt index cb8a3a00cc92..df904aec9904 100644 --- a/Documentation/flexible-arrays.txt +++ b/Documentation/flexible-arrays.txt @@ -66,10 +66,10 @@ trick is to ensure that any needed memory allocations are done before entering atomic context, using: int flex_array_prealloc(struct flex_array *array, unsigned int start, - unsigned int end, gfp_t flags); + unsigned int nr_elements, gfp_t flags); This function will ensure that memory for the elements indexed in the range -defined by start and end has been allocated. Thereafter, a +defined by start and nr_elements has been allocated. Thereafter, a flex_array_put() call on an element in that range is guaranteed not to block. diff --git a/Documentation/hwmon/adm1021 b/Documentation/hwmon/adm1021 index 03d02bfb3df1..02ad96cf9b2b 100644 --- a/Documentation/hwmon/adm1021 +++ b/Documentation/hwmon/adm1021 @@ -14,10 +14,6 @@ Supported chips: Prefix: 'gl523sm' Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e Datasheet: - * Intel Xeon Processor - Prefix: - any other - may require 'force_adm1021' parameter - Addresses scanned: none - Datasheet: Publicly available at Intel website * Maxim MAX1617 Prefix: 'max1617' Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e @@ -91,21 +87,27 @@ will do no harm, but will return 'old' values. It is possible to make ADM1021-clones do faster measurements, but there is really no good reason for that. -Xeon support ------------- -Some Xeon processors have real max1617, adm1021, or compatible chips -within them, with two temperature sensors. +Netburst-based Xeon support +--------------------------- -Other Xeons have chips with only one sensor. +Some Xeon processors based on the Netburst (early Pentium 4, from 2001 to +2003) microarchitecture had real MAX1617, ADM1021, or compatible chips +within them, with two temperature sensors. Other Xeon processors of this +era (with 400 MHz FSB) had chips with only one temperature sensor. -If you have a Xeon, and the adm1021 module loads, and both temperatures -appear valid, then things are good. +If you have such an old Xeon, and you get two valid temperatures when +loading the adm1021 module, then things are good. -If the adm1021 module doesn't load, you should try this: - modprobe adm1021 force_adm1021=BUS,ADDRESS - ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. +If nothing happens when loading the adm1021 module, and you are certain +that your specific Xeon processor model includes compatible sensors, you +will have to explicitly instantiate the sensor chips from user-space. See +method 4 in Documentation/i2c/instantiating-devices. Possible slave +addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that +only temp2 will be correct and temp1 will have to be ignored. -If you have dual Xeons you may have appear to have two separate -adm1021-compatible chips, or two single-temperature sensors, at distinct -addresses. +Previous generations of the Xeon processor (based on Pentium II/III) +didn't have these sensors. Next generations of Xeon processors (533 MHz +FSB and faster) lost them, until the Core-based generation which +introduced integrated digital thermal sensors. These are supported by +the coretemp driver. diff --git a/Documentation/hwmon/lm90 b/Documentation/hwmon/lm90 index fa475c0a48a3..f3efd18e87f4 100644 --- a/Documentation/hwmon/lm90 +++ b/Documentation/hwmon/lm90 @@ -32,6 +32,16 @@ Supported chips: Addresses scanned: I2C 0x4c and 0x4d Datasheet: Publicly available at the ON Semiconductor website http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461 + * Analog Devices ADT7461A + Prefix: 'adt7461a' + Addresses scanned: I2C 0x4c and 0x4d + Datasheet: Publicly available at the ON Semiconductor website + http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461A + * ON Semiconductor NCT1008 + Prefix: 'nct1008' + Addresses scanned: I2C 0x4c and 0x4d + Datasheet: Publicly available at the ON Semiconductor website + http://www.onsemi.com/PowerSolutions/product.do?id=NCT1008 * Maxim MAX6646 Prefix: 'max6646' Addresses scanned: I2C 0x4d @@ -149,7 +159,7 @@ ADM1032: * ALERT is triggered by open remote sensor. * SMBus PEC support for Write Byte and Receive Byte transactions. -ADT7461: +ADT7461, ADT7461A, NCT1008: * Extended temperature range (breaks compatibility) * Lower resolution for remote temperature @@ -195,9 +205,9 @@ are exported, one for each channel, but these values are of course linked. Only the local hysteresis can be set from user-space, and the same delta applies to the remote hysteresis. -The lm90 driver will not update its values more frequently than every -other second; reading them more often will do no harm, but will return -'old' values. +The lm90 driver will not update its values more frequently than configured with +the update_interval attribute; reading them more often will do no harm, but will +return 'old' values. SMBus Alert Support ------------------- @@ -205,11 +215,12 @@ SMBus Alert Support This driver has basic support for SMBus alert. When an alert is received, the status register is read and the faulty temperature channel is logged. -The Analog Devices chips (ADM1032 and ADT7461) do not implement the SMBus -alert protocol properly so additional care is needed: the ALERT output is -disabled when an alert is received, and is re-enabled only when the alarm -is gone. Otherwise the chip would block alerts from other chips in the bus -as long as the alarm is active. +The Analog Devices chips (ADM1032, ADT7461 and ADT7461A) and ON +Semiconductor chips (NCT1008) do not implement the SMBus alert protocol +properly so additional care is needed: the ALERT output is disabled when +an alert is received, and is re-enabled only when the alarm is gone. +Otherwise the chip would block alerts from other chips in the bus as long +as the alarm is active. PEC Support ----------- diff --git a/Documentation/hwmon/max16064 b/Documentation/hwmon/max16064 new file mode 100644 index 000000000000..41728999e142 --- /dev/null +++ b/Documentation/hwmon/max16064 @@ -0,0 +1,62 @@ +Kernel driver max16064 +====================== + +Supported chips: + * Maxim MAX16064 + Prefix: 'max16064' + Addresses scanned: - + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX16064.pdf + +Author: Guenter Roeck <guenter.roeck@ericsson.com> + + +Description +----------- + +This driver supports hardware montoring for Maxim MAX16064 Quad Power-Supply +Controller with Active-Voltage Output Control and PMBus Interface. + +The driver is a client driver to the core PMBus driver. +Please see Documentation/hwmon/pmbus for details on PMBus client drivers. + + +Usage Notes +----------- + +This driver does not auto-detect devices. You will have to instantiate the +devices explicitly. Please see Documentation/i2c/instantiating-devices for +details. + + +Platform data support +--------------------- + +The driver supports standard PMBus driver platform data. + + +Sysfs entries +------------- + +The following attributes are supported. Limits are read-write; all other +attributes are read-only. + +in[1-4]_label "vout[1-4]" +in[1-4]_input Measured voltage. From READ_VOUT register. +in[1-4]_min Minumum Voltage. From VOUT_UV_WARN_LIMIT register. +in[1-4]_max Maximum voltage. From VOUT_OV_WARN_LIMIT register. +in[1-4]_lcrit Critical minumum Voltage. VOUT_UV_FAULT_LIMIT register. +in[1-4]_crit Critical maximum voltage. From VOUT_OV_FAULT_LIMIT register. +in[1-4]_min_alarm Voltage low alarm. From VOLTAGE_UV_WARNING status. +in[1-4]_max_alarm Voltage high alarm. From VOLTAGE_OV_WARNING status. +in[1-4]_lcrit_alarm Voltage critical low alarm. From VOLTAGE_UV_FAULT status. +in[1-4]_crit_alarm Voltage critical high alarm. From VOLTAGE_OV_FAULT status. + +temp1_input Measured temperature. From READ_TEMPERATURE_1 register. +temp1_max Maximum temperature. From OT_WARN_LIMIT register. +temp1_crit Critical high temperature. From OT_FAULT_LIMIT register. +temp1_max_alarm Chip temperature high alarm. Set by comparing + READ_TEMPERATURE_1 with OT_WARN_LIMIT if TEMP_OT_WARNING + status is set. +temp1_crit_alarm Chip temperature critical high alarm. Set by comparing + READ_TEMPERATURE_1 with OT_FAULT_LIMIT if TEMP_OT_FAULT + status is set. diff --git a/Documentation/hwmon/max34440 b/Documentation/hwmon/max34440 new file mode 100644 index 000000000000..6c525dd07d59 --- /dev/null +++ b/Documentation/hwmon/max34440 @@ -0,0 +1,79 @@ +Kernel driver max34440 +====================== + +Supported chips: + * Maxim MAX34440 + Prefixes: 'max34440' + Addresses scanned: - + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34440.pdf + * Maxim MAX34441 + PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller + Prefixes: 'max34441' + Addresses scanned: - + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34441.pdf + +Author: Guenter Roeck <guenter.roeck@ericsson.com> + + +Description +----------- + +This driver supports hardware montoring for Maxim MAX34440 PMBus 6-Channel +Power-Supply Manager and MAX34441 PMBus 5-Channel Power-Supply Manager +and Intelligent Fan Controller. + +The driver is a client driver to the core PMBus driver. Please see +Documentation/hwmon/pmbus for details on PMBus client drivers. + + +Usage Notes +----------- + +This driver does not auto-detect devices. You will have to instantiate the +devices explicitly. Please see Documentation/i2c/instantiating-devices for +details. + + +Platform data support +--------------------- + +The driver supports standard PMBus driver platform data. + + +Sysfs entries +------------- + +The following attributes are supported. Limits are read-write; all other +attributes are read-only. + +in[1-6]_label "vout[1-6]". +in[1-6]_input Measured voltage. From READ_VOUT register. +in[1-6]_min Minumum Voltage. From VOUT_UV_WARN_LIMIT register. +in[1-6]_max Maximum voltage. From VOUT_OV_WARN_LIMIT register. +in[1-6]_lcrit Critical minumum Voltage. VOUT_UV_FAULT_LIMIT register. +in[1-6]_crit Critical maximum voltage. From VOUT_OV_FAULT_LIMIT register. +in[1-6]_min_alarm Voltage low alarm. From VOLTAGE_UV_WARNING status. +in[1-6]_max_alarm Voltage high alarm. From VOLTAGE_OV_WARNING status. +in[1-6]_lcrit_alarm Voltage critical low alarm. From VOLTAGE_UV_FAULT status. +in[1-6]_crit_alarm Voltage critical high alarm. From VOLTAGE_OV_FAULT status. + +curr[1-6]_label "iout[1-6]". +curr[1-6]_input Measured current. From READ_IOUT register. +curr[1-6]_max Maximum current. From IOUT_OC_WARN_LIMIT register. +curr[1-6]_crit Critical maximum current. From IOUT_OC_FAULT_LIMIT register. +curr[1-6]_max_alarm Current high alarm. From IOUT_OC_WARNING status. +curr[1-6]_crit_alarm Current critical high alarm. From IOUT_OC_FAULT status. + + in6 and curr6 attributes only exist for MAX34440. + +temp[1-8]_input Measured temperatures. From READ_TEMPERATURE_1 register. + temp1 is the chip's internal temperature. temp2..temp5 + are remote I2C temperature sensors. For MAX34441, temp6 + is a remote thermal-diode sensor. For MAX34440, temp6..8 + are remote I2C temperature sensors. +temp[1-8]_max Maximum temperature. From OT_WARN_LIMIT register. +temp[1-8]_crit Critical high temperature. From OT_FAULT_LIMIT register. +temp[1-8]_max_alarm Temperature high alarm. +temp[1-8]_crit_alarm Temperature critical high alarm. + + temp7 and temp8 attributes only exist for MAX34440. diff --git a/Documentation/hwmon/max8688 b/Documentation/hwmon/max8688 new file mode 100644 index 000000000000..0ddd3a412030 --- /dev/null +++ b/Documentation/hwmon/max8688 @@ -0,0 +1,69 @@ +Kernel driver max8688 +===================== + +Supported chips: + * Maxim MAX8688 + Prefix: 'max8688' + Addresses scanned: - + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8688.pdf + +Author: Guenter Roeck <guenter.roeck@ericsson.com> + + +Description +----------- + +This driver supports hardware montoring for Maxim MAX8688 Digital Power-Supply +Controller/Monitor with PMBus Interface. + +The driver is a client driver to the core PMBus driver. Please see +Documentation/hwmon/pmbus for details on PMBus client drivers. + + +Usage Notes +----------- + +This driver does not auto-detect devices. You will have to instantiate the +devices explicitly. Please see Documentation/i2c/instantiating-devices for +details. + + +Platform data support +--------------------- + +The driver supports standard PMBus driver platform data. + + +Sysfs entries +------------- + +The following attributes are supported. Limits are read-write; all other +attributes are read-only. + +in1_label "vout1" +in1_input Measured voltage. From READ_VOUT register. +in1_min Minumum Voltage. From VOUT_UV_WARN_LIMIT register. +in1_max Maximum voltage. From VOUT_OV_WARN_LIMIT register. +in1_lcrit Critical minumum Voltage. VOUT_UV_FAULT_LIMIT register. +in1_crit Critical maximum voltage. From VOUT_OV_FAULT_LIMIT register. +in1_min_alarm Voltage low alarm. From VOLTAGE_UV_WARNING status. +in1_max_alarm Voltage high alarm. From VOLTAGE_OV_WARNING status. +in1_lcrit_alarm Voltage critical low alarm. From VOLTAGE_UV_FAULT status. +in1_crit_alarm Voltage critical high alarm. From VOLTAGE_OV_FAULT status. + +curr1_label "iout1" +curr1_input Measured current. From READ_IOUT register. +curr1_max Maximum current. From IOUT_OC_WARN_LIMIT register. +curr1_crit Critical maximum current. From IOUT_OC_FAULT_LIMIT register. +curr1_max_alarm Current high alarm. From IOUT_OC_WARN_LIMIT register. +curr1_crit_alarm Current critical high alarm. From IOUT_OC_FAULT status. + +temp1_input Measured temperature. From READ_TEMPERATURE_1 register. +temp1_max Maximum temperature. From OT_WARN_LIMIT register. +temp1_crit Critical high temperature. From OT_FAULT_LIMIT register. +temp1_max_alarm Chip temperature high alarm. Set by comparing + READ_TEMPERATURE_1 with OT_WARN_LIMIT if TEMP_OT_WARNING + status is set. +temp1_crit_alarm Chip temperature critical high alarm. Set by comparing + READ_TEMPERATURE_1 with OT_FAULT_LIMIT if TEMP_OT_FAULT + status is set. diff --git a/Documentation/hwmon/pmbus b/Documentation/hwmon/pmbus index dc4933e96344..5e462fc7f99b 100644 --- a/Documentation/hwmon/pmbus +++ b/Documentation/hwmon/pmbus @@ -13,26 +13,6 @@ Supported chips: Prefix: 'ltc2978' Addresses scanned: - Datasheet: http://cds.linear.com/docs/Datasheet/2978fa.pdf - * Maxim MAX16064 - Quad Power-Supply Controller - Prefix: 'max16064' - Addresses scanned: - - Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX16064.pdf - * Maxim MAX34440 - PMBus 6-Channel Power-Supply Manager - Prefixes: 'max34440' - Addresses scanned: - - Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34440.pdf - * Maxim MAX34441 - PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller - Prefixes: 'max34441' - Addresses scanned: - - Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34441.pdf - * Maxim MAX8688 - Digital Power-Supply Controller/Monitor - Prefix: 'max8688' - Addresses scanned: - - Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8688.pdf * Generic PMBus devices Prefix: 'pmbus' Addresses scanned: - @@ -175,11 +155,13 @@ currX_crit Critical maximum current. From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register. currX_alarm Current high alarm. From IIN_OC_WARNING or IOUT_OC_WARNING status. +currX_max_alarm Current high alarm. + From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status. currX_lcrit_alarm Output current critical low alarm. From IOUT_UC_FAULT status. currX_crit_alarm Current critical high alarm. From IIN_OC_FAULT or IOUT_OC_FAULT status. -currX_label "iin" or "vinY" +currX_label "iin" or "ioutY" powerX_input Measured power. From READ_PIN or READ_POUT register. powerX_cap Output power cap. From POUT_MAX register. @@ -193,13 +175,13 @@ powerX_crit_alarm Output power critical high alarm. From POUT_OP_FAULT status. powerX_label "pin" or "poutY" -tempX_input Measured tempererature. +tempX_input Measured temperature. From READ_TEMPERATURE_X register. -tempX_min Mimimum tempererature. From UT_WARN_LIMIT register. -tempX_max Maximum tempererature. From OT_WARN_LIMIT register. -tempX_lcrit Critical low tempererature. +tempX_min Mimimum temperature. From UT_WARN_LIMIT register. +tempX_max Maximum temperature. From OT_WARN_LIMIT register. +tempX_lcrit Critical low temperature. From UT_FAULT_LIMIT register. -tempX_crit Critical high tempererature. +tempX_crit Critical high temperature. From OT_FAULT_LIMIT register. tempX_min_alarm Chip temperature low alarm. Set by comparing READ_TEMPERATURE_X with UT_WARN_LIMIT if diff --git a/Documentation/hwmon/smm665 b/Documentation/hwmon/smm665 index 3820fc9ca52d..59e316140542 100644 --- a/Documentation/hwmon/smm665 +++ b/Documentation/hwmon/smm665 @@ -150,8 +150,8 @@ in8_crit_alarm Channel F critical alarm in9_crit_alarm AIN1 critical alarm in10_crit_alarm AIN2 critical alarm -temp1_input Chip tempererature -temp1_min Mimimum chip tempererature -temp1_max Maximum chip tempererature -temp1_crit Critical chip tempererature +temp1_input Chip temperature +temp1_min Mimimum chip temperature +temp1_max Maximum chip temperature +temp1_crit Critical chip temperature temp1_crit_alarm Temperature critical alarm diff --git a/Documentation/hwmon/submitting-patches b/Documentation/hwmon/submitting-patches new file mode 100644 index 000000000000..86f42e8e9e49 --- /dev/null +++ b/Documentation/hwmon/submitting-patches @@ -0,0 +1,109 @@ + How to Get Your Patch Accepted Into the Hwmon Subsystem + ------------------------------------------------------- + +This text is is a collection of suggestions for people writing patches or +drivers for the hwmon subsystem. Following these suggestions will greatly +increase the chances of your change being accepted. + + +1. General +---------- + +* It should be unnecessary to mention, but please read and follow + Documentation/SubmitChecklist + Documentation/SubmittingDrivers + Documentation/SubmittingPatches + Documentation/CodingStyle + +* If your patch generates checkpatch warnings, please refrain from explanations + such as "I don't like that coding style". Keep in mind that each unnecessary + warning helps hiding a real problem. If you don't like the kernel coding + style, don't write kernel drivers. + +* Please test your patch thoroughly. We are not your test group. + Sometimes a patch can not or not completely be tested because of missing + hardware. In such cases, you should test-build the code on at least one + architecture. If run-time testing was not achieved, it should be written + explicitly below the patch header. + +* If your patch (or the driver) is affected by configuration options such as + CONFIG_SMP or CONFIG_HOTPLUG, make sure it compiles for all configuration + variants. + + +2. Adding functionality to existing drivers +------------------------------------------- + +* Make sure the documentation in Documentation/hwmon/<driver_name> is up to + date. + +* Make sure the information in Kconfig is up to date. + +* If the added functionality requires some cleanup or structural changes, split + your patch into a cleanup part and the actual addition. This makes it easier + to review your changes, and to bisect any resulting problems. + +* Never mix bug fixes, cleanup, and functional enhancements in a single patch. + + +3. New drivers +-------------- + +* Running your patch or driver file(s) through checkpatch does not mean its + formatting is clean. If unsure about formatting in your new driver, run it + through Lindent. Lindent is not perfect, and you may have to do some minor + cleanup, but it is a good start. + +* Consider adding yourself to MAINTAINERS. + +* Document the driver in Documentation/hwmon/<driver_name>. + +* Add the driver to Kconfig and Makefile in alphabetical order. + +* Make sure that all dependencies are listed in Kconfig. For new drivers, it + is most likely prudent to add a dependency on EXPERIMENTAL. + +* Avoid forward declarations if you can. Rearrange the code if necessary. + +* Avoid calculations in macros and macro-generated functions. While such macros + may save a line or so in the source, it obfuscates the code and makes code + review more difficult. It may also result in code which is more complicated + than necessary. Use inline functions or just regular functions instead. + +* If the driver has a detect function, make sure it is silent. Debug messages + and messages printed after a successful detection are acceptable, but it + must not print messages such as "Chip XXX not found/supported". + + Keep in mind that the detect function will run for all drivers supporting an + address if a chip is detected on that address. Unnecessary messages will just + pollute the kernel log and not provide any value. + +* Provide a detect function if and only if a chip can be detected reliably. + +* Avoid writing to chip registers in the detect function. If you have to write, + only do it after you have already gathered enough data to be certain that the + detection is going to be successful. + + Keep in mind that the chip might not be what your driver believes it is, and + writing to it might cause a bad misconfiguration. + +* Make sure there are no race conditions in the probe function. Specifically, + completely initialize your chip first, then create sysfs entries and register + with the hwmon subsystem. + +* Do not provide support for deprecated sysfs attributes. + +* Do not create non-standard attributes unless really needed. If you have to use + non-standard attributes, or you believe you do, discuss it on the mailing list + first. Either case, provide a detailed explanation why you need the + non-standard attribute(s). + Standard attributes are specified in Documentation/hwmon/sysfs-interface. + +* When deciding which sysfs attributes to support, look at the chip's + capabilities. While we do not expect your driver to support everything the + chip may offer, it should at least support all limits and alarms. + +* Last but not least, please check if a driver for your chip already exists + before starting to write a new driver. Especially for temperature sensors, + new chips are often variants of previously released chips. In some cases, + a presumably new chip may simply have been relabeled. diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt new file mode 100644 index 000000000000..23fcb05175be --- /dev/null +++ b/Documentation/input/event-codes.txt @@ -0,0 +1,262 @@ +The input protocol uses a map of types and codes to express input device values +to userspace. This document describes the types and codes and how and when they +may be used. + +A single hardware event generates multiple input events. Each input event +contains the new value of a single data item. A special event type, EV_SYN, is +used to separate input events into packets of input data changes occurring at +the same moment in time. In the following, the term "event" refers to a single +input event encompassing a type, code, and value. + +The input protocol is a stateful protocol. Events are emitted only when values +of event codes have changed. However, the state is maintained within the Linux +input subsystem; drivers do not need to maintain the state and may attempt to +emit unchanged values without harm. Userspace may obtain the current state of +event code values using the EVIOCG* ioctls defined in linux/input.h. The event +reports supported by a device are also provided by sysfs in +class/input/event*/device/capabilities/, and the properties of a device are +provided in class/input/event*/device/properties. + +Types: +========== +Types are groupings of codes under a logical input construct. Each type has a +set of applicable codes to be used in generating events. See the Codes section +for details on valid codes for each type. + +* EV_SYN: + - Used as markers to separate events. Events may be separated in time or in + space, such as with the multitouch protocol. + +* EV_KEY: + - Used to describe state changes of keyboards, buttons, or other key-like + devices. + +* EV_REL: + - Used to describe relative axis value changes, e.g. moving the mouse 5 units + to the left. + +* EV_ABS: + - Used to describe absolute axis value changes, e.g. describing the + coordinates of a touch on a touchscreen. + +* EV_MSC: + - Used to describe miscellaneous input data that do not fit into other types. + +* EV_SW: + - Used to describe binary state input switches. + +* EV_LED: + - Used to turn LEDs on devices on and off. + +* EV_SND: + - Used to output sound to devices. + +* EV_REP: + - Used for autorepeating devices. + +* EV_FF: + - Used to send force feedback commands to an input device. + +* EV_PWR: + - A special type for power button and switch input. + +* EV_FF_STATUS: + - Used to receive force feedback device status. + +Codes: +========== +Codes define the precise type of event. + +EV_SYN: +---------- +EV_SYN event values are undefined. Their usage is defined only by when they are +sent in the evdev event stream. + +* SYN_REPORT: + - Used to synchronize and separate events into packets of input data changes + occurring at the same moment in time. For example, motion of a mouse may set + the REL_X and REL_Y values for one motion, then emit a SYN_REPORT. The next + motion will emit more REL_X and REL_Y values and send another SYN_REPORT. + +* SYN_CONFIG: + - TBD + +* SYN_MT_REPORT: + - Used to synchronize and separate touch events. See the + multi-touch-protocol.txt document for more information. + +* SYN_DROPPED: + - Used to indicate buffer overrun in the evdev client's event queue. + Client should ignore all events up to and including next SYN_REPORT + event and query the device (using EVIOCG* ioctls) to obtain its + current state. + +EV_KEY: +---------- +EV_KEY events take the form KEY_<name> or BTN_<name>. For example, KEY_A is used +to represent the 'A' key on a keyboard. When a key is depressed, an event with +the key's code is emitted with value 1. When the key is released, an event is +emitted with value 0. Some hardware send events when a key is repeated. These +events have a value of 2. In general, KEY_<name> is used for keyboard keys, and +BTN_<name> is used for other types of momentary switch events. + +A few EV_KEY codes have special meanings: + +* BTN_TOOL_<name>: + - These codes are used in conjunction with input trackpads, tablets, and + touchscreens. These devices may be used with fingers, pens, or other tools. + When an event occurs and a tool is used, the corresponding BTN_TOOL_<name> + code should be set to a value of 1. When the tool is no longer interacting + with the input device, the BTN_TOOL_<name> code should be reset to 0. All + trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name> + code when events are generated. + +* BTN_TOUCH: + BTN_TOUCH is used for touch contact. While an input tool is determined to be + within meaningful physical contact, the value of this property must be set + to 1. Meaningful physical contact may mean any contact, or it may mean + contact conditioned by an implementation defined property. For example, a + touchpad may set the value to 1 only when the touch pressure rises above a + certain value. BTN_TOUCH may be combined with BTN_TOOL_<name> codes. For + example, a pen tablet may set BTN_TOOL_PEN to 1 and BTN_TOUCH to 0 while the + pen is hovering over but not touching the tablet surface. + +Note: For appropriate function of the legacy mousedev emulation driver, +BTN_TOUCH must be the first evdev code emitted in a synchronization frame. + +Note: Historically a touch device with BTN_TOOL_FINGER and BTN_TOUCH was +interpreted as a touchpad by userspace, while a similar device without +BTN_TOOL_FINGER was interpreted as a touchscreen. For backwards compatibility +with current userspace it is recommended to follow this distinction. In the +future, this distinction will be deprecated and the device properties ioctl +EVIOCGPROP, defined in linux/input.h, will be used to convey the device type. + +* BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, BTN_TOOL_TRIPLETAP, BTN_TOOL_QUADTAP: + - These codes denote one, two, three, and four finger interaction on a + trackpad or touchscreen. For example, if the user uses two fingers and moves + them on the touchpad in an effort to scroll content on screen, + BTN_TOOL_DOUBLETAP should be set to value 1 for the duration of the motion. + Note that all BTN_TOOL_<name> codes and the BTN_TOUCH code are orthogonal in + purpose. A trackpad event generated by finger touches should generate events + for one code from each group. At most only one of these BTN_TOOL_<name> + codes should have a value of 1 during any synchronization frame. + +Note: Historically some drivers emitted multiple of the finger count codes with +a value of 1 in the same synchronization frame. This usage is deprecated. + +Note: In multitouch drivers, the input_mt_report_finger_count() function should +be used to emit these codes. Please see multi-touch-protocol.txt for details. + +EV_REL: +---------- +EV_REL events describe relative changes in a property. For example, a mouse may +move to the left by a certain number of units, but its absolute position in +space is unknown. If the absolute position is known, EV_ABS codes should be used +instead of EV_REL codes. + +A few EV_REL codes have special meanings: + +* REL_WHEEL, REL_HWHEEL: + - These codes are used for vertical and horizontal scroll wheels, + respectively. + +EV_ABS: +---------- +EV_ABS events describe absolute changes in a property. For example, a touchpad +may emit coordinates for a touch location. + +A few EV_ABS codes have special meanings: + +* ABS_DISTANCE: + - Used to describe the distance of a tool from an interaction surface. This + event should only be emitted while the tool is hovering, meaning in close + proximity of the device and while the value of the BTN_TOUCH code is 0. If + the input device may be used freely in three dimensions, consider ABS_Z + instead. + +* ABS_MT_<name>: + - Used to describe multitouch input events. Please see + multi-touch-protocol.txt for details. + +EV_SW: +---------- +EV_SW events describe stateful binary switches. For example, the SW_LID code is +used to denote when a laptop lid is closed. + +Upon binding to a device or resuming from suspend, a driver must report +the current switch state. This ensures that the device, kernel, and userspace +state is in sync. + +Upon resume, if the switch state is the same as before suspend, then the input +subsystem will filter out the duplicate switch state reports. The driver does +not need to keep the state of the switch at any time. + +EV_MSC: +---------- +EV_MSC events are used for input and output events that do not fall under other +categories. + +EV_LED: +---------- +EV_LED events are used for input and output to set and query the state of +various LEDs on devices. + +EV_REP: +---------- +EV_REP events are used for specifying autorepeating events. + +EV_SND: +---------- +EV_SND events are used for sending sound commands to simple sound output +devices. + +EV_FF: +---------- +EV_FF events are used to initialize a force feedback capable device and to cause +such device to feedback. + +EV_PWR: +---------- +EV_PWR events are a special type of event used specifically for power +mangement. Its usage is not well defined. To be addressed later. + +Guidelines: +========== +The guidelines below ensure proper single-touch and multi-finger functionality. +For multi-touch functionality, see the multi-touch-protocol.txt document for +more information. + +Mice: +---------- +REL_{X,Y} must be reported when the mouse moves. BTN_LEFT must be used to report +the primary button press. BTN_{MIDDLE,RIGHT,4,5,etc.} should be used to report +further buttons of the device. REL_WHEEL and REL_HWHEEL should be used to report +scroll wheel events where available. + +Touchscreens: +---------- +ABS_{X,Y} must be reported with the location of the touch. BTN_TOUCH must be +used to report when a touch is active on the screen. +BTN_{MOUSE,LEFT,MIDDLE,RIGHT} must not be reported as the result of touch +contact. BTN_TOOL_<name> events should be reported where possible. + +Trackpads: +---------- +Legacy trackpads that only provide relative position information must report +events like mice described above. + +Trackpads that provide absolute touch position must report ABS_{X,Y} for the +location of the touch. BTN_TOUCH should be used to report when a touch is active +on the trackpad. Where multi-finger support is available, BTN_TOOL_<name> should +be used to report the number of touches active on the trackpad. + +Tablets: +---------- +BTN_TOOL_<name> events must be reported when a stylus or other tool is active on +the tablet. ABS_{X,Y} must be reported with the location of the tool. BTN_TOUCH +should be used to report when the tool is in contact with the tablet. +BTN_{STYLUS,STYLUS2} should be used to report buttons on the tool itself. Any +button may be used for buttons on the tablet except BTN_{MOUSE,LEFT}. +BTN_{0,1,2,etc} are good generic codes for unlabeled buttons. Do not use +meaningful buttons, like BTN_FORWARD, unless the button is labeled for that +purpose on the device. diff --git a/Documentation/md.txt b/Documentation/md.txt index a81c7b4790f2..2366b1c8cf19 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -552,6 +552,16 @@ also have within the array where IO will be blocked. This is currently only supported for raid4/5/6. + sync_min + sync_max + The two values, given as numbers of sectors, indicate a range + withing the array where 'check'/'repair' will operate. Must be + a multiple of chunk_size. When it reaches "sync_max" it will + pause, rather than complete. + You can use 'select' or 'poll' on "sync_completed" to wait for + that number to reach sync_max. Then you can either increase + "sync_max", or can write 'idle' to "sync_action". + Each active md device may also have attributes specific to the personality module that manages it. diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt index 9822afb6313c..89757012c7ff 100644 --- a/Documentation/sound/alsa/ALSA-Configuration.txt +++ b/Documentation/sound/alsa/ALSA-Configuration.txt @@ -1230,6 +1230,13 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. This module supports multiple cards. The driver requires the firmware loader support on kernel. + Module snd-lola + --------------- + + Module for Digigram Lola PCI-e boards + + This module supports multiple cards. + Module snd-lx6464es ------------------- diff --git a/Documentation/video4linux/sh_mobile_ceu_camera.txt b/Documentation/video4linux/sh_mobile_ceu_camera.txt index cb47e723af74..1e96ce6e2d2f 100644 --- a/Documentation/video4linux/sh_mobile_ceu_camera.txt +++ b/Documentation/video4linux/sh_mobile_ceu_camera.txt @@ -37,7 +37,7 @@ Generic scaling / cropping scheme -1'- In the above chart minuses and slashes represent "real" data amounts, points and -accents represent "useful" data, basically, CEU scaled amd cropped output, +accents represent "useful" data, basically, CEU scaled and cropped output, mapped back onto the client's source plane. Such a configuration can be produced by user requests: @@ -65,7 +65,7 @@ Do not touch input rectangle - it is already optimal. 1. Calculate current sensor scales: - scale_s = ((3') - (3)) / ((2') - (2)) + scale_s = ((2') - (2)) / ((3') - (3)) 2. Calculate "effective" input crop (sensor subwindow) - CEU crop scaled back at current sensor scales onto input window - this is user S_CROP: @@ -80,7 +80,7 @@ window: 4. Calculate sensor output window by applying combined scales to real input window: - width_s_out = ((2') - (2)) / scale_comb + width_s_out = ((7') - (7)) = ((2') - (2)) / scale_comb 5. Apply iterative sensor S_FMT for sensor output window. diff --git a/Documentation/workqueue.txt b/Documentation/workqueue.txt index 01c513fac40e..a0b577de918f 100644 --- a/Documentation/workqueue.txt +++ b/Documentation/workqueue.txt @@ -12,6 +12,7 @@ CONTENTS 4. Application Programming Interface (API) 5. Example Execution Scenarios 6. Guidelines +7. Debugging 1. Introduction @@ -379,3 +380,42 @@ If q1 has WQ_CPU_INTENSIVE set, * Unless work items are expected to consume a huge amount of CPU cycles, using a bound wq is usually beneficial due to the increased level of locality in wq operations and work item execution. + + +7. Debugging + +Because the work functions are executed by generic worker threads +there are a few tricks needed to shed some light on misbehaving +workqueue users. + +Worker threads show up in the process list as: + +root 5671 0.0 0.0 0 0 ? S 12:07 0:00 [kworker/0:1] +root 5672 0.0 0.0 0 0 ? S 12:07 0:00 [kworker/1:2] +root 5673 0.0 0.0 0 0 ? S 12:12 0:00 [kworker/0:0] +root 5674 0.0 0.0 0 0 ? S 12:13 0:00 [kworker/1:0] + +If kworkers are going crazy (using too much cpu), there are two types +of possible problems: + + 1. Something beeing scheduled in rapid succession + 2. A single work item that consumes lots of cpu cycles + +The first one can be tracked using tracing: + + $ echo workqueue:workqueue_queue_work > /sys/kernel/debug/tracing/set_event + $ cat /sys/kernel/debug/tracing/trace_pipe > out.txt + (wait a few secs) + ^C + +If something is busy looping on work queueing, it would be dominating +the output and the offender can be determined with the work item +function. + +For the second type of problems it should be possible to just check +the stack trace of the offending worker thread. + + $ cat /proc/THE_OFFENDING_KWORKER/stack + +The work item's function should be trivially visible in the stack +trace. |