diff options
| author | David Jander <david@protonic.nl> | 2020-11-11 11:00:59 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-30 11:25:54 +0100 |
| commit | 5173b3900126b1d8b75331a3528c2ae8eebb7ae5 (patch) | |
| tree | 2bf570890876bc2e7de7183a31e082e859a14578 | |
| parent | 0d4a8dd1a3eec63a7b2e6f4ffd9922d5fbc4bc30 (diff) | |
Input: ads7846 - fix race that causes missing releases
[ Upstream commit e52cd628a03f72a547dbf90ccb703ee64800504a ]
If touchscreen is released while busy reading HWMON device, the release
can be missed. The IRQ thread is not started because no touch is active
and BTN_TOUCH release event is never sent.
Fixes: f5a28a7d4858f94a ("Input: ads7846 - avoid pen up/down when reading hwmon")
Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20201027105416.18773-1-o.rempel@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index a2f45aefce08..0fbad337e45a 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -199,6 +199,26 @@ struct ads7846 { #define REF_ON (READ_12BIT_DFR(x, 1, 1)) #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) +static int get_pendown_state(struct ads7846 *ts) +{ + if (ts->get_pendown_state) + return ts->get_pendown_state(); + + return !gpio_get_value(ts->gpio_pendown); +} + +static void ads7846_report_pen_up(struct ads7846 *ts) +{ + struct input_dev *input = ts->input; + + input_report_key(input, BTN_TOUCH, 0); + input_report_abs(input, ABS_PRESSURE, 0); + input_sync(input); + + ts->pendown = false; + dev_vdbg(&ts->spi->dev, "UP\n"); +} + /* Must be called with ts->lock held */ static void ads7846_stop(struct ads7846 *ts) { @@ -215,6 +235,10 @@ static void ads7846_stop(struct ads7846 *ts) static void ads7846_restart(struct ads7846 *ts) { if (!ts->disabled && !ts->suspended) { + /* Check if pen was released since last stop */ + if (ts->pendown && !get_pendown_state(ts)) + ads7846_report_pen_up(ts); + /* Tell IRQ thread that it may poll the device. */ ts->stopped = false; mb(); @@ -605,14 +629,6 @@ static const struct attribute_group ads784x_attr_group = { /*--------------------------------------------------------------------------*/ -static int get_pendown_state(struct ads7846 *ts) -{ - if (ts->get_pendown_state) - return ts->get_pendown_state(); - - return !gpio_get_value(ts->gpio_pendown); -} - static void null_wait_for_sync(void) { } @@ -871,16 +887,8 @@ static irqreturn_t ads7846_irq(int irq, void *handle) msecs_to_jiffies(TS_POLL_PERIOD)); } - if (ts->pendown && !ts->stopped) { - struct input_dev *input = ts->input; - - input_report_key(input, BTN_TOUCH, 0); - input_report_abs(input, ABS_PRESSURE, 0); - input_sync(input); - - ts->pendown = false; - dev_vdbg(&ts->spi->dev, "UP\n"); - } + if (ts->pendown && !ts->stopped) + ads7846_report_pen_up(ts); return IRQ_HANDLED; } |