6.12-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
[ Upstream commit 99f2211a9d89fe34b3fa847fd7a4475171406cd0 ]
probe() requests the reset GPIO to be set to high when getting it. Immeditately after this hi556_resume() is called and sets the GPIO low.
If the GPIO was low before requesting it this will result in the GPIO only very briefly spiking high and the sensor not being properly reset. The same problem also happens on back to back runtime suspend + resume.
Fix this by adding a sleep of 2 ms in hi556_resume() before setting the GPIO low (if there is a reset GPIO).
The final sleep is kept unconditional, because if there is e.g. no reset GPIO but a controllable clock then the sensor also needs some time after enabling the clock.
Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com Signed-off-by: Hans Verkuil hverkuil@xs4all.nl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/i2c/hi556.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c index 0e89aff9c664..3c84cf07275f 100644 --- a/drivers/media/i2c/hi556.c +++ b/drivers/media/i2c/hi556.c @@ -1321,7 +1321,12 @@ static int hi556_resume(struct device *dev) return ret; }
- gpiod_set_value_cansleep(hi556->reset_gpio, 0); + if (hi556->reset_gpio) { + /* Assert reset for at least 2ms on back to back off-on */ + usleep_range(2000, 2200); + gpiod_set_value_cansleep(hi556->reset_gpio, 0); + } + usleep_range(5000, 5500); return 0; }