There is a small chance that ts->suspending flag may change while the interrupt handler is running. To make sure call to pm_relax() is not skipped on accident use a temporary to hold the original value at the beginning of interrupt. Use READ_ONCE() so that the value is actually fetched at the right time. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> --- drivers/input/touchscreen/zforce_ts.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c index afeafa589928..004ef728fb90 100644 --- a/drivers/input/touchscreen/zforce_ts.c +++ b/drivers/input/touchscreen/zforce_ts.c @@ -454,6 +454,7 @@ static irqreturn_t zforce_irq_thread(int irq, void *dev_id) int ret; u8 payload_buffer[FRAME_MAXSIZE]; u8 *payload; + bool suspending; /* * When still suspended, return. @@ -467,7 +468,8 @@ static irqreturn_t zforce_irq_thread(int irq, void *dev_id) dev_dbg(&client->dev, "handling interrupt\n"); /* Don't emit wakeup events from commands run by zforce_suspend */ - if (!ts->suspending && device_may_wakeup(&client->dev)) + suspending = READ_ONCE(ts->suspending); + if (!suspending && device_may_wakeup(&client->dev)) pm_stay_awake(&client->dev); /* @@ -495,7 +497,7 @@ static irqreturn_t zforce_irq_thread(int irq, void *dev_id) * Always report touch-events received while * suspending, when being a wakeup source */ - if (ts->suspending && device_may_wakeup(&client->dev)) + if (suspending && device_may_wakeup(&client->dev)) pm_wakeup_event(&client->dev, 500); zforce_touch_event(ts, &payload[RESPONSE_DATA]); break; @@ -548,7 +550,7 @@ static irqreturn_t zforce_irq_thread(int irq, void *dev_id) } } while (gpiod_get_value_cansleep(ts->gpio_int)); - if (!ts->suspending && device_may_wakeup(&client->dev)) + if (!suspending && device_may_wakeup(&client->dev)) pm_relax(&client->dev); dev_dbg(&client->dev, "finished interrupt\n"); @@ -584,7 +586,9 @@ static int zforce_suspend(struct device *dev) int ret = 0; mutex_lock(&input->mutex); - ts->suspending = true; + + WRITE_ONCE(ts->suspending, true); + smp_mb(); /* * When configured as a wakeup source device should always wake @@ -615,7 +619,9 @@ static int zforce_suspend(struct device *dev) ts->suspended = true; unlock: - ts->suspending = false; + smp_mb(); + WRITE_ONCE(ts->suspending, false); + mutex_unlock(&input->mutex); return ret; -- 2.46.0.295.g3b9ea8a38a-goog
