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path: root/drivers/mmc/core/core.c
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2016-09-26mmc: core: don't try to switch block size for dual rate modeZiyuan Xu
Per spec, block size should always be 512 bytes for dual rate mode, so any attempts to switch the block size under dual rate mode should be neglected. Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-09-26mmc: core: Add support for sending commands during data transferAdrian Hunter
A host controller driver exposes its capability using caps flag MMC_CAP_CMD_DURING_TFR. A driver with that capability can accept requests that are marked mrq->cap_cmd_during_tfr = true. Then the driver informs the upper layers when the command line is available for further commands by calling mmc_command_done(). Because of that, the driver will not then automatically send STOP commands, and it is the responsibility of the upper layer to send a STOP command if it is required. For requests submitted through the mmc_wait_for_req() interface, the caller sets mrq->cap_cmd_during_tfr = true which causes mmc_wait_for_req() in fact not to wait. The caller can then send commands that do not use the data lines. Finally the caller can wait for the transfer to complete by calling mmc_wait_for_req_done() which is now exported. For requests submitted through the mmc_start_req() interface, the caller again sets mrq->cap_cmd_during_tfr = true, but mmc_start_req() anyway does not wait. The caller can then send commands that do not use the data lines. Finally the caller can wait for the transfer to complete in the normal way i.e. calling mmc_start_req() again. Irrespective of how a cap_cmd_during_tfr request is started, mmc_is_req_done() can be called if the upper layer needs to determine if the request is done. However the appropriate waiting function (either mmc_wait_for_req_done() or mmc_start_req()) must still be called. The implementation consists primarily of a new completion mrq->cmd_completion which notifies when the command line is available for further commands. That completion is completed by mmc_command_done(). When there is an ongoing data transfer, calls to mmc_wait_for_req() will automatically wait on that completion, so the caller does not have to do anything special. Note, in the case of errors, the driver may call mmc_request_done() without calling mmc_command_done() because mmc_request_done() always calls mmc_command_done(). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-09-26mmc: core: Optimize the mmc erase size alignmentBaolin Wang
In most cases the 'card->erase_size' is power of 2, then the round_up/down() function is more efficient than '%' operation when the 'card->erase_size' is power of 2. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Tested-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-09-26mmc: core: Factor out the alignment of erase sizeBaolin Wang
In order to clean up the mmc_erase() function and do some optimization for erase size alignment, factor out the guts of erase size alignment into mmc_align_erase_size() function. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Tested-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-09-26mmc: core: Use a default maximum erase timeoutUlf Hansson
In cases when the host->max_busy_timeout isn't specified, the calculated number of maximum discard sectors defaults to UINT_MAX. This may cause a too long timeout for a discard request. Avoid this by using a default maximum erase timeout of 60s, used when we calculate the maximum number of sectors that are allowed to be discarded per request. Do note that the minimum number of sectors to be discarded is still at least one "preferred erase size". Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
2016-07-25mmc: Change the max discard sectors and erase response when HW busy detectBaolin Wang
When mmc host HW supports busy signalling (using R1B as response), don't use the host->max_busy_timeout as the limitation when deciding the max discard sectors, which we inform the generic BLOCK layer about. Instead, let's use at least one preferred erase size as the max discard sectors. In cases when the host controller supports HW busy signalling and the timeout for the erase operation doesn't exceed the max_busy_timeout, we keep the R1B response, otherwise we prevent the host from doing HW busy detection by converting to a R1 response. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25mmc: core: Allow hosts to specify non-support for MMC commandsShawn Lin
Host drivers which needs to valdiate for non-supported MMC commands and returnn error code for such requests. To improve and simplify the behaviour, let's invent MMC_CAP2_NO_MMC which these host drivers can set to tell the mmc core to skip sending MMC commands during card initialization. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25mmc: core: Allow hosts to specify non-support for SD commandsUlf Hansson
There are host drivers which needs to valdiate for non-supported SD commands and returnn error code for such requests. To improve and simplify the behaviour, let's invent MMC_CAP2_NO_SD which these host drivers can set to tell the mmc core to skip sending SD commands during card initialization. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25mmc: Set pref erase size based on sizeGwendal Grignou
If available, eMMC stack uses HC_ERASE_GRP_SIZE as the preferred erase size. As some high capacity eMMC (64MB) reports this size to 512kB, the discard operations end up taking very long time. Improve the behaviour by instead calculating the preferred erase size based on the eMMC size. In this way the discard operations becomes faster. Signed-off-by: Gwendal Grignou <gwendal@chromium.org> [Ulf: Updated changelog and improved comment in code] Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25mmc: core: implement enhanced strobe supportShawn Lin
Controllers use data strobe line to latch data from devices under hs400 mode, but not for cmd line. So since emmc 5.1, JEDEC introduces enhanced strobe mode for latching cmd response from emmc devices to host controllers. This new feature is optional, so it depends both on device's cap and host's cap to decide whether to use it or not. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com> Tested-by: Douglas Anderson <dianders@chromium.org> Tested-by: Jaehoon Chung <jh80.chung@samsung.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-23mmc: longer timeout for long read time quirkMatt Gumbel
008GE0 Toshiba mmc in some Intel Baytrail tablets responds to MMC_SEND_EXT_CSD in 450-600ms. This patch will... () Increase the long read time quirk timeout from 300ms to 600ms. Original author of that quirk says 300ms was only a guess and that the number may need to be raised in the future. () Add this specific MMC to the quirk Signed-off-by: Matt Gumbel <matthew.k.gumbel@intel.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-02mmc: core: Do regular power cycle when lacking eMMC HW reset supportGwendal Grignou
The eMMC HW reset may be implemented either via the host ops ->hw_reset() callback or through DT and the eMMC pwrseq. Additionally some eMMC cards don't support HW reset. To allow a reset to be done for the different combinations of mmc hosts and eMMC/MMC cards, let's implement a fallback via trying a regular power cycle. This improves the mmc block layer retry mechanism of failing I/O requests. Signed-off-by: Gwendal Grignou <gwendal@chromium.org> [Ulf: Rewrote changelog] Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-02mmc: core: Provide tracepoints for request processingBaolin Wang
This patch provides some tracepoints for the lifecycle of a mmc request from starting to completion to help with performance analysis of MMC subsystem. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-02-29mmc: core: report tuning command execution failure reasonRussell King
Print the error code when the tuning command fails. This allows the reason for the failure to be reported, which aids debugging. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-02-29mmc: core: improve mmc_of_parse_voltage() to return better statusRussell King
Improve mmc_of_parse_voltage()'s return values so that drivers can tell whether a voltage-range specification was present, and whether it has been successfully parsed, or there was an error while parsing. We return a negative errno when parsing fails, zero if no voltage-range specification is present, or one if a voltage-range specification is successfully parsed. No users need modifying as no users check the return value. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-02-29mmc: core: shut up "voltage-ranges unspecified" pr_info()Russell King
Each time a driver such as sdhci-esdhc-imx is probed, we get a info printk complaining that the DT voltage-ranges property has not been specified. However, the DT binding specifically says that the voltage-ranges property is optional. That means we should not be complaining that DT hasn't specified this property: by indicating that it's optional, it is valid not to have the property in DT. Silence the warning if the property is missing. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-02-29mmc: sanitize 'bus width' in debug outputWolfram Sang
The bus width is sometimes the actual bus width, and sometimes indices to different arrays encoding the bus width. In my debugging case "2" could mean 8-bit as well as 4-bit, which was extremly confusing. Let's use the human-readable actual bus width in all places. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-02-29mmc: core: use the defined function to check whether card is removableJaehoon Chung
In linux/mmc/host.h, mmc_card_is_removable() is already defined. There is no reason that it doesn't use. Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-28mmc: core: Optimize boot time by detecting cards simultaneouslyUlf Hansson
The mmc workqueue is an ordered workqueue, allowing only one work to execute per given time. As this workqueue is used for card detection, the conseqeunce is that cards will be detected one by one waiting for each other. Moreover, most of the time spent during card initialization is waiting for the card's internal firmware to be ready. From a CPU perspective this typically means waiting for a completion variable to be kicked via an IRQ-handler or waiting for a sleep timer to finish. This behaviour of detecting/initializing cards is sub-optimal, especially for SOCs having several controllers/cards. Let's convert to use the system_freezable_wq for the mmc detect works. This enables several works to be executed simultaneously and thus also cards to be detected like so. Tests on UX500, which holds two eMMC cards and an SD-card (actually also an SDIO card, currently not detected), shows a significant improved behaviour due to this change. Before this change, both the eMMC cards waited for the SD card to be initialized as its detect work entered the workqueue first. In some cases, depending on the characteristic of the SD-card, they got delayed 1-1.5 s. Additionally for the second eMMC, it needed to wait for the first eMMC to be initialized which added another 120-190 ms. Converting to the system_freezable_wq, removed these delays and made both the eMMC cards available far earlier in the boot sequence. Selecting the system_freezable_wq, in favour of for example the system_wq, is because we need card detection mechanism to be disabled once userspace are frozen during system PM. Currently the mmc core deal with this via PM notifiers, but following patches may utilize the behaviour of the system_freezable_wq, to simplify the use of the PM notifiers. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Alan Cooper <alcooperx@gmail.com> Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
2015-12-22mmc: core: Introduce MMC_CAP2_NO_SDIO capCarlo Caione
This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc core to not send SDIO specific commands. Signed-off-by: Carlo Caione <carlo@endlessm.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22mmc: core: set regulator not found message as debugludovic.desroches@atmel.com
Turn the informative message about no vmmc/vqmmc regulator found in debug one. There is no need to indicate that something optional is missing. Moreover, it can bring confusion, people who doesn't know it is optional may consider these messages as warnings or errors. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22mmc: core: Check for non-removable cards earlier in the error pathUlf Hansson
_mmc_detect_card_removed() validates that the card is removable, but when being called via the bus_ops ->detect() callbacks, the validation is redundant as it's already done in mmc_rescan(). Move the validation of a removable card to the mmc_detect_card_removed() API, which is where it's applicable, to allow the blk error recovery path to get the response a bit earlier. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22mmc: core: Refactor code to register the MMC PM notifierUlf Hansson
Instead of checking for "#ifdef" directly in the code, let's invent a pair of mmc core functions to deal with register/unregister the MMC PM notifier block. Implement stubs for these functions when CONFIG_PM_SLEEP is unset, as in that case the PM notifiers isn't used. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22mmc: core: Keep host claimed in mmc_rescan() while calling host opsUlf Hansson
As mmc_claim_host() invokes pm_runtime_get_sync() for the mmc host device, it's important that the host is kept claimed for *all* accesses to it via the host_ops callbacks. In mmc_rescan(), the ->card_event() and the ->get_cd() callback are being invoked without claiming the host, let's fix this. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22mmc: core: Invoke ->card_event() callback only when neededUlf Hansson
The ->card_event() callback may be called when re-scan is disabled and for non-removable cards, which both cases are unnecessary. Instead let's move the call later in mmc_rescan() where these constraints have been validated. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26mmc: core: Add mmc_regulator_set_vqmmc()Douglas Anderson
This adds logic to the MMC core to set VQMMC. This is expected to be called by MMC drivers like dw_mmc as part of (or instead of) their start_signal_voltage_switch() callback. A few notes: * When setting the signal voltage to 3.3V we do our best to make VQMMC and VMMC match. It's been reported that this makes some old cards happy since they were tested back in the day before UHS when VQMMC and VMMC were provided by the same regulator. A nice side effect of this is that we don't end up on the hairy edge of VQMMC (2.7V), which some EEs claim is a little too close to the minimum for comfort. This is done in two steps. At first we try to find a VQMMC within a 0.3V tolerance of VMMC and if this is not supported by the supplying regulator we try to find a suitable voltage within the whole 2.7V-3.6V area of the spec. * The two step approach is currently necessary, as the used regulator_set_voltage_triplet(min, target, max) uses a simple implementation that just tries two basic steps: regulator_set_voltage(target, max); regulator_set_voltage(min, target); So with only one step with 2.7-3.6V borders, if a suitable voltage is a bit below VMMC, we would directly get the lowest 2.7V which some boards (like Rockchips) don't like at all. * When setting the signal voltage to 1.8V or 1.2V we aim for that specific voltage instead of picking the lowest one in the range. * We very purposely don't print errors in mmc_regulator_set_vqmmc(). There are cases where the MMC core will try several different voltages and we don't want to pollute the logs. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26mmc: core: move ocr-bit to voltage translation into separate functionHeiko Stuebner
We will shortly need the calculation of an ocr-bit to the actual voltage in a second place too, so move it from mmc_regulator_set_ocr to a common function mmc_ocrbitnum_to_vdd to make that possible. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26mmc: core: Remove MMC_CLKGATEUlf Hansson
MMC_CLKGATE was once invented to save power by gating the bus clock at request inactivity. At that time it served its purpose. The modern way to deal with power saving for these scenarios, is by using runtime PM. Nowadays, several host drivers have deployed runtime PM, but for those that haven't and which still cares power saving at request inactivity, it's certainly time to deploy runtime PM as it has been around for several years now. To simplify code to mmc core and thus decrease maintenance efforts, this patch removes all code related to MMC_CLKGATE. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-26mmc: Wait for card_busy before starting sdio requestsHans de Goede
Some sdio wifi chips will not work properly if we try to start new sdio-rw requests while the device is signalling that it is busy. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26mmc: core: Keep host claimed while invoking mmc_power_off|up()Ulf Hansson
As mmc_claim_host() invokes pm_runtime_get_sync() for the mmc host device, it's important that the host is kept claimed for *all* accesses to it via the host_ops callbacks. In some code paths for SDIO, particularly related to the PM support, mmc_power_off|up() is invoked without keeping the host claimed. Let's fix these. Moreover, mmc_start|stop_host() also invokes mmc_power_off|up() without claiming the host, let's fix these as well. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
2015-09-30mmc: core: fix dead loop of mmc_retuneChaotian Jing
When get a CRC error, start the mmc_retune, it will issue CMD19/CMD21 to do tune, assume there were 10 clock phase need to try, phase 0 to phase 6 is ok, phase 7 to phase 9 is NG, we try it from 0 to 9, so the last CMD19/CMD21 will get CRC error, host->need_retune was set and cause mmc_retune was called, then dead loop of mmc_retune Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors") Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-08-31mmc: core: fix race condition in mmc_wait_data_doneJialing Fu
The following panic is captured in ker3.14, but the issue still exists in latest kernel. --------------------------------------------------------------------- [ 20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference at virtual address 00000578 ...... [ 20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60 [ 20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60 [ 20.740134] c0 3136 (Compiler) Call trace: [ 20.740165] c0 3136 (Compiler) [<ffffffc0008ee900>] _raw_spin_lock_irqsave+0x24/0x60 [ 20.740200] c0 3136 (Compiler) [<ffffffc0000dd024>] __wake_up+0x1c/0x54 [ 20.740230] c0 3136 (Compiler) [<ffffffc000639414>] mmc_wait_data_done+0x28/0x34 [ 20.740262] c0 3136 (Compiler) [<ffffffc0006391a0>] mmc_request_done+0xa4/0x220 [ 20.740314] c0 3136 (Compiler) [<ffffffc000656894>] sdhci_tasklet_finish+0xac/0x264 [ 20.740352] c0 3136 (Compiler) [<ffffffc0000a2b58>] tasklet_action+0xa0/0x158 [ 20.740382] c0 3136 (Compiler) [<ffffffc0000a2078>] __do_softirq+0x10c/0x2e4 [ 20.740411] c0 3136 (Compiler) [<ffffffc0000a24bc>] irq_exit+0x8c/0xc0 [ 20.740439] c0 3136 (Compiler) [<ffffffc00008489c>] handle_IRQ+0x48/0xac [ 20.740469] c0 3136 (Compiler) [<ffffffc000081428>] gic_handle_irq+0x38/0x7c ---------------------------------------------------------------------- Because in SMP, "mrq" has race condition between below two paths: path1: CPU0: <tasklet context> static void mmc_wait_data_done(struct mmc_request *mrq) { mrq->host->context_info.is_done_rcv = true; // // If CPU0 has just finished "is_done_rcv = true" in path1, and at // this moment, IRQ or ICache line missing happens in CPU0. // What happens in CPU1 (path2)? // // If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode: // path2 would have chance to break from wait_event_interruptible // in mmc_wait_for_data_req_done and continue to run for next // mmc_request (mmc_blk_rw_rq_prep). // // Within mmc_blk_rq_prep, mrq is cleared to 0. // If below line still gets host from "mrq" as the result of // compiler, the panic happens as we traced. wake_up_interruptible(&mrq->host->context_info.wait); } path2: CPU1: <The mmcqd thread runs mmc_queue_thread> static int mmc_wait_for_data_req_done(... { ... while (1) { wait_event_interruptible(context_info->wait, (context_info->is_done_rcv || context_info->is_new_req)); static void mmc_blk_rw_rq_prep(... { ... memset(brq, 0, sizeof(struct mmc_blk_request)); This issue happens very coincidentally; however adding mdelay(1) in mmc_wait_data_done as below could duplicate it easily. static void mmc_wait_data_done(struct mmc_request *mrq) { mrq->host->context_info.is_done_rcv = true; + mdelay(1); wake_up_interruptible(&mrq->host->context_info.wait); } At runtime, IRQ or ICache line missing may just happen at the same place of the mdelay(1). This patch gets the mmc_context_info at the beginning of function, it can avoid this race condition. Signed-off-by: Jialing Fu <jlfu@marvell.com> Tested-by: Shawn Lin <shawn.lin@rock-chips.com> Fixes: 2220eedfd7ae ("mmc: fix async request mechanism ....") Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-08-27mmc: block: skip trim for some kingston eMMCsShawn Lin
For some mass production of kingston eMMCs which adopt Phison's firmware will meet an unrecoverable data conrruption occasionally if performing trim due to a firmware bug confirmed by vendor. We found it on Intel-C3230RK platform. So we add fixup of broken trim for it. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-08-27mmc: core: Fixed bug in one erase-group budget TRIMRobin van der Gracht
When requesting a trim for several bytes, everything up to the next erase-group is erased. This causes data corruption. Signed-off-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-08-17mmc: core: Optimize case for exactly one erase-group budgetDavid Jander
In the (not so unlikely) case that the mmc controller timeout budget is enough for exactly one erase-group, the simplification of allowing one sector has an enormous performance penalty. We optimize this special case by introducing a flag that prohibits erase-group boundary crossing, so that we can allow trimming more than one sector at a time. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Factor out common code in drive strength selectionAdrian Hunter
Make a new function out of common code used for drive strength selection. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Reset driver type to defaultAdrian Hunter
IO state variable drv_type could be set during card initialization. Consequently, it must be reset to the default value when setting the initial state. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Increase delay for voltage to stabilize from 3.3V to 1.8VDoug Anderson
Since the regulator used for the SDMMC IO voltage is not expected to draw a lot of current, most systems will probably use an inexpensive LDO for it. LDO regulators apparently have the feature that they don't actively drive the voltage down--they wait for other components in the system to drag the voltage down. Thus they will transition faster under heavy loads and slower under light loads. During an SDMMC voltage change from 3.3V to 1.8V, we are almost certainly under a light load. To be specific: * The regulator is hooked through pulls to CMD0-3 and DAT. Probably the CMD pulls are something like 47K and the DAT is something like 10K. * The card is supposed to be driving DAT0-3 low during voltage change which will draw _some_ current, but not a lot. * The regulator is also provided to the SDMMC host controller, but the SDMMC host controller is in open drain mode during the voltage change and so shouldn't be drawing much current. In order to keep the SDMMC host working properly (or for noise reasons), there might also be a capacitor attached to the SDMMC IO regulator. This also will have the effect of slowing down transitions of the regulator, especially under light loads. From experimental evidence, we've seen the voltage change fail if the card doesn't detect that the voltage fell to less than about 2.3V when we turn on the clock. On one device (that admittedly had a 47K CMD pullup instead of a 10K CMD pullup) we saw that the voltage was just about 2.3V after 5ms and thus the voltage change would sometimes fail. Doubling the delay gave margin and made the voltage change work 100% of the time, despite the slightly weaker CMD pull. At the moment submitting this as an RFC patch since my problem _could_ be fixed by increasing the pull strength (or using a smaller capacitor). However being a little bit more lenient to strange hardware could also be a good thing. Signed-off-by: Doug Anderson <dianders@chromium.org> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Don't print reset warning if reset is not supportedAdrian Hunter
Check the error code for EOPNOTSUPP and do not print reset warning in that case. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Flag re-tuning is needed on CRC errorsAdrian Hunter
CRC errors could possibly be alleviated by re-tuning so flag re-tuning needed in those cases. Note this has no effect if re-tuning has not been enabled. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Hold re-tuning while bkops ongoingAdrian Hunter
Hold re-tuning during bkops to prevent it from conflicting with the busy state. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Hold re-tuning during erase commandsAdrian Hunter
Hold re-tuning during erase commands to prevent it from conflicting with the sequence of commands. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Add support for re-tuning before each requestAdrian Hunter
At the start of each request, re-tune if needed and then hold off re-tuning again until the request is done. Note that though there is one function that starts requests (mmc_start_request) there are two that wait for the request to be done (mmc_wait_for_req_done and mmc_wait_for_data_req_done). Also note that mmc_wait_for_data_req_done can return even when the request is not done (which allows the block driver to prepare a newly arrived request while still waiting for the previous request). This patch ensures re-tuning is held for the duration of a request. Subsequent patches will also hold re-tuning at other times when it might cause a conflict. In addition, possibly a command is failing because re-tuning is needed. Use mmc_retune_recheck() to check re-tuning. At that point re-tuning is held, at least by the request, so mmc_retune_recheck() flags host->retune_now if the hold count is 1. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01mmc: core: Enable / disable re-tuningAdrian Hunter
Enable re-tuning when tuning is executed and disable re-tuning when card is no longer initialized. In the case of SDIO suspend, the card can keep power. In that case, re-tuning need not be disabled, but, if a re-tuning timer is being used, ensure it is disabled and assume that re-tuning will be needed upon resume since it is not known how long the suspend will last. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-05-04mmc: core: add missing pm event in mmc_pm_notify to fix hib restoreGrygorii Strashko
The PM_RESTORE_PREPARE is not handled now in mmc_pm_notify(), as result mmc_rescan() could be scheduled and executed at late hibernation restore stages when MMC device is suspended already - which, in turn, will lead to system crash on TI dra7-evm board: WARNING: CPU: 0 PID: 3188 at drivers/bus/omap_l3_noc.c:148 l3_interrupt_handler+0x258/0x374() 44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4_PER1_P3 (Idle): Data Access in User mode during Functional access Hence, add missed PM_RESTORE_PREPARE PM event in mmc_pm_notify(). Fixes: 4c2ef25fe0b8 (mmc: fix all hangs related to mmc/sd card...) Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-03-31mmc: core: Enable runtime PM management of host devicesUlf Hansson
Currently those host drivers which have deployed runtime PM, deals with the runtime PM reference counting entirely by themselves. Since host drivers don't know when the core will send the next request through some of the host_ops callbacks, they need to handle runtime PM get/put between each an every request. In quite many cases this has some negative effects, since it leads to a high frequency of scheduled runtime PM suspend operations. That due to the runtime PM reference count will normally reach zero in-between every request. We can decrease that frequency, by enabling the core to deal with runtime PM reference counting of the host device. Since the core often knows that it will send a seqeunce of requests, it makes sense for it to keep a runtime PM reference count during these periods. More exactly, let's increase the runtime PM reference count by invoking pm_runtime_get_sync() from __mmc_claim_host(). Restore that action by invoking pm_runtime_mark_last_busy() and pm_runtime_put_autosuspend() in mmc_release_host(). In this way a runtime PM reference count will be kept during the complete cycle of a claim -> release host. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Konstantin Dorfman <kdorfman@codeaurora.org>
2015-03-27mmc: core: Remove the ->enable|disable() callbacksNeilBrown
These callbacks have been set to deprecated for some time. The last user (omap_hsmmc) has moved away from using them, which thus enables us to completely remove them. Signed-off-by: NeilBrown <neil@brown.name> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-02-03mmc: core: Invoke mmc_pwrseq_post_power_on() prior MMC_POWER_ON stateUlf Hansson
Host drivers have different ways to sends their "init stream" to the card. Some need to do it as part of a request, some do it from the ->set_ios() callback in the MMC_POWER_ON state and some don't send an "init stream" at all. To be able to use the reset GPIOs from the simple MMC power sequence provider, the card need to be powered and the "init stream" must not have been sent. To cope with these requirements, invoke mmc_pwrseq_post_power_on() prior we change the state to MMC_POWER_ON in mmc_power_up(). Host drivers shall perform power up operations in the MMC_POWER_UP state. Unfortunate three hosts (au1xmmc, cb710-mmc and toshsd) don't conform to this expectation. Instead those ignore the MMC_POWER_UP state and delays their power up operations to the MMC_POWER_ON state. Those hosts needs to change their behavior to enable proper support for the simple MMC power sequence provider. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
2015-01-29mmc: Resolve BKOPS compatability issueAlexey Skidanov
This patch is coming to fix compatibility issue of BKOPS_EN field of EXT_CSD. In eMMC-5.1, BKOPS_EN was changed, and now it has two operational bits: Bit 0 - MANUAL_EN Bit 1 - AUTO_EN In previous eMMC revisions, only Bit 0 was supported. Signed-off-by: Alexey Skidanov <alexey.skidanov@sandisk.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-28mmc: core: Initial support for MMC power sequencesUlf Hansson
System on chip designs may specify a specific MMC power sequence. To successfully detect an (e)MMC/SD/SDIO card, that power sequence must be followed while initializing the card. To be able to handle these SOC specific power sequences, let's add a MMC power sequence interface. It provides the following functions to help the mmc core to deal with these power sequences. mmc_pwrseq_alloc() - Invoked from mmc_of_parse(), to initialize data. mmc_pwrseq_pre_power_on()- Invoked in the beginning of mmc_power_up(). mmc_pwrseq_post_power_on()- Invoked at the end in mmc_power_up(). mmc_pwrseq_power_off()- Invoked from mmc_power_off(). mmc_pwrseq_free() - Invoked from mmc_free_host(), to free data. Each MMC power sequence provider will be responsible to implement a set of callbacks. These callbacks mirrors the functions above. This patch adds the skeleton, following patches will extend the core of the MMC power sequence and add support for a specific simple MMC power sequence. Do note, since the mmc_pwrseq_alloc() is invoked from mmc_of_parse(), host drivers needs to make use of this API to enable the support for MMC power sequences. Moreover the MMC power sequence support depends on CONFIG_OF. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>