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authorJason Gerecke <killertofu@gmail.com>2017-01-26 09:06:22 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-09 08:08:29 +0100
commite6bd712154aaf121bff1791431854886f5983712 (patch)
tree6ffd4efb9e00b8c520f13f8c5eef0ac552c73fb3
parentf24bc920612ccc68edb8ff4ee6e117a3e0a52304 (diff)
HID: wacom: Fix poor prox handling in 'wacom_pl_irq'
commit 282e4637bc1c0b338708bcebd09d31c69abec070 upstream. Commit 025bcc1 performed cleanup work on the 'wacom_pl_irq' function, making it follow the standards used in the rest of the codebase. The change unintiontionally allowed the function to send input events from reports that are not marked as being in prox. This can cause problems as the report values for X, Y, etc. are not guaranteed to be correct. In particular, occasionally the tablet will send a report with these values set to zero. If such a report is received it can caus an unexpected jump in the XY position. This patch surrounds more of the processing code with a proximity check, preventing these zeroed reports from overwriting the current state. To be safe, only the tool type and ABS_MISC events should be reported when the pen is marked as being out of prox. Fixes: 025bcc1540 ("HID: wacom: Simplify 'wacom_pl_irq'") Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com> Reviewed-by: Ping Cheng <pingc@wacom.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/hid/wacom_wac.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 1cb79925730d..623be90704ab 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -164,19 +164,21 @@ static int wacom_pl_irq(struct wacom_wac *wacom)
wacom->id[0] = STYLUS_DEVICE_ID;
}
- pressure = (signed char)((data[7] << 1) | ((data[4] >> 2) & 1));
- if (features->pressure_max > 255)
- pressure = (pressure << 1) | ((data[4] >> 6) & 1);
- pressure += (features->pressure_max + 1) / 2;
-
- input_report_abs(input, ABS_X, data[3] | (data[2] << 7) | ((data[1] & 0x03) << 14));
- input_report_abs(input, ABS_Y, data[6] | (data[5] << 7) | ((data[4] & 0x03) << 14));
- input_report_abs(input, ABS_PRESSURE, pressure);
-
- input_report_key(input, BTN_TOUCH, data[4] & 0x08);
- input_report_key(input, BTN_STYLUS, data[4] & 0x10);
- /* Only allow the stylus2 button to be reported for the pen tool. */
- input_report_key(input, BTN_STYLUS2, (wacom->tool[0] == BTN_TOOL_PEN) && (data[4] & 0x20));
+ if (prox) {
+ pressure = (signed char)((data[7] << 1) | ((data[4] >> 2) & 1));
+ if (features->pressure_max > 255)
+ pressure = (pressure << 1) | ((data[4] >> 6) & 1);
+ pressure += (features->pressure_max + 1) / 2;
+
+ input_report_abs(input, ABS_X, data[3] | (data[2] << 7) | ((data[1] & 0x03) << 14));
+ input_report_abs(input, ABS_Y, data[6] | (data[5] << 7) | ((data[4] & 0x03) << 14));
+ input_report_abs(input, ABS_PRESSURE, pressure);
+
+ input_report_key(input, BTN_TOUCH, data[4] & 0x08);
+ input_report_key(input, BTN_STYLUS, data[4] & 0x10);
+ /* Only allow the stylus2 button to be reported for the pen tool. */
+ input_report_key(input, BTN_STYLUS2, (wacom->tool[0] == BTN_TOOL_PEN) && (data[4] & 0x20));
+ }
if (!prox)
wacom->id[0] = 0;