Hi Evan, On Tue, Sep 24, 2019 at 02:52:38PM -0700, Evan Green wrote: > Across suspend and resume, we are seeing error messages like the following: > > atmel_mxt_ts i2c-PRP0001:00: __mxt_read_reg: i2c transfer failed (-121) > atmel_mxt_ts i2c-PRP0001:00: Failed to read T44 and T5 (-121) > > This occurs because the driver leaves its IRQ enabled. Upon resume, there > is an IRQ pending, but the interrupt is serviced before both the driver and > the underlying I2C bus have been resumed. This causes EREMOTEIO errors. > > Disable the IRQ in suspend, and re-enable it on resume. If there are cases > where the driver enters suspend with interrupts disabled, that's a bug we > should fix separately. > > Signed-off-by: Evan Green <evgr...@chromium.org> > --- > > Changes in v2: > - Enable and disable unconditionally (Dmitry) > > drivers/input/touchscreen/atmel_mxt_ts.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c > b/drivers/input/touchscreen/atmel_mxt_ts.c > index 24c4b691b1c9..a58092488679 100644 > --- a/drivers/input/touchscreen/atmel_mxt_ts.c > +++ b/drivers/input/touchscreen/atmel_mxt_ts.c > @@ -3155,6 +3155,7 @@ static int __maybe_unused mxt_suspend(struct device > *dev) > mxt_stop(data); > > mutex_unlock(&input_dev->mutex); > + disable_irq(data->irq); > > return 0; > } > @@ -3174,6 +3175,7 @@ static int __maybe_unused mxt_resume(struct device *dev) > mxt_start(data); > > mutex_unlock(&input_dev->mutex); > + enable_irq(data->irq);
At least for older devices that do soft reset on resume we need interrupts to already work when we call mxt_start(). In general, order of resume steps should mirror suspend. Thanks. -- Dmitry
