Re: [PATCH] da9052: ensure da9052_ts_input_open will not lock up on irq flood
flat view
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2016-03-11 19:33:14
On Thu, Mar 03, 2016 at 11:52:02AM +0100, Michael Grzeschik wrote:
It is possible that da9052_ts_input_open is called and the touchscreen is triggering continuous interrupts. In this case we will never leave da9052_ts_input_open. The da9052_reg_update will never get the i2c bus as the interrupt handler will continuously lock it. This patch switch places of da9052_reg_update and the setting of tsi->stopped. This way its ensured that da9052_ts_input_open will never lockup on interrupt flood.
I understand what you are saying about updating register, however I do not understand why we would want to swap unmasking pendown event ans clearing the "stopped" flag. Thanks.
quoted hunk ↗ jump to hunk
Signed-off-by: Michael Grzeschik <redacted> --- drivers/input/touchscreen/da9052_tsi.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c index 5a013bb..1b136b8 100644 --- a/drivers/input/touchscreen/da9052_tsi.c +++ b/drivers/input/touchscreen/da9052_tsi.c@@ -189,17 +189,20 @@ static int da9052_configure_tsi(struct da9052_tsi *tsi) static int da9052_ts_input_open(struct input_dev *input_dev) { + int val; struct da9052_tsi *tsi = input_get_drvdata(input_dev); - tsi->stopped = false; - mb(); + val = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, + 1 << 1, 1 << 1); /* Unmask PEN_DOWN event */ da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN); + tsi->stopped = false; + mb(); + /* Enable Pen Detect Circuit */ - return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, - 1 << 1, 1 << 1); + return val; } static void da9052_ts_input_close(struct input_dev *input_dev)-- 2.7.0
-- Dmitry