diff options
| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-08-23 22:50:31 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-09-05 22:56:45 -0700 |
| commit | 9ba33f6145728c09c8e4578ffa8e94aef47b4e68 (patch) | |
| tree | a9f5957cfca3b68a78afa7aec38f4e29811ed01a /drivers/input | |
| parent | f388412f707e98735e44341447263ab3e25e7043 (diff) | |
Input: zforce_ts - ensure that pm_stay_awake() and pm_relax() are balanced
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.
Tested-by: Andreas Kemnade <andreas@kemnade.info> # Tolino Shine2HD
Link: https://lore.kernel.org/r/20240824055047.1706392-8-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/touchscreen/zforce_ts.c | 16 |
1 files 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; |