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authorMarek Vasut <marex@denx.de>2015-05-07 22:25:49 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2015-05-07 22:30:18 -0700
commit9ceeb59c5f7e4c4612039323f4266cabb3baedfd (patch)
tree8417e66075bc4aeb89dcc7fe63a2ba91e316df33
parentInput: smtpe-ts - use msecs_to_jiffies() instead of HZ (diff)
downloadlinux-dev-9ceeb59c5f7e4c4612039323f4266cabb3baedfd.tar.xz
linux-dev-9ceeb59c5f7e4c4612039323f4266cabb3baedfd.zip
Input: smtpe-ts - wait 50mS until polling for pen-up
Wait a little bit longer, 50mS instead of 20mS, until the driver starts polling for pen-up. The problematic behavior before this patch is applied is as follows. The behavior was observed on the STMPE610QTR controller. Upon a physical pen-down event, the touchscreen reports one set of x-y-p coordinates and a pen-down event. After that, the pen-up polling is triggered and since the controller is not ready yet, the polling mistakenly detects a pen-up event while the physical state is still such that the pen is down on the touch surface. The pen-up handling flushes the controller FIFO, so after that, all the samples in the controller are discarded. The controller becomes ready shortly after this bogus pen-up handling and does generate again a pen-down interrupt. This time, the controller contains x-y-p samples which all read as zero. Since pressure value is zero, this set of samples is effectively ignored by userland. In the end, the driver just bounces between pen-down and bogus pen-up handling, generating no useful results. Fix this by giving the controller a bit more time before polling it for pen-up. Signed-off-by: Marek Vasut <marex@denx.de> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
-rw-r--r--drivers/input/touchscreen/stmpe-ts.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
index 702ad200d916..e4c31256a74d 100644
--- a/drivers/input/touchscreen/stmpe-ts.c
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -164,7 +164,7 @@ static irqreturn_t stmpe_ts_handler(int irq, void *data)
STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
/* start polling for touch_det to detect release */
- schedule_delayed_work(&ts->work, msecs_to_jiffies(20));
+ schedule_delayed_work(&ts->work, msecs_to_jiffies(50));
return IRQ_HANDLED;
}