| Message ID | 20180203120046.10988-1-zbsdta@126.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi! On Sat, Feb 03, 2018 at 08:00:46PM +0800, Zhang Bo wrote: > From: zhangbo <zbsdta@126.com> > > If matrix_keypad_stop() is calling and the keypad interrupt is triggered, > disable_row_irqs() is called by both matrix_keypad_interrupt() and > matrix_keypad_stop() at the same time. then disable_row_irqs() is called > twice, and the device enter suspend state before keypad->work is executed. > At this condition the device will start keypad and enable irq once after > resume. and then irqs are disabled yet because irqs are disabled twice and > only enable once. > > Signed-off-by: zhangbo <zbsdta@126.com> Please use your full real name in the signed-off-by tag. > --- > drivers/input/keyboard/matrix_keypad.c | 18 ++++++++++++------ > 1 file changed, 12 insertions(+), 6 deletions(-) > > diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c > index 1f316d66e6f7..13fe51824637 100644 > --- a/drivers/input/keyboard/matrix_keypad.c > +++ b/drivers/input/keyboard/matrix_keypad.c > @@ -169,7 +169,8 @@ static void matrix_keypad_scan(struct work_struct *work) > /* Enable IRQs again */ > spin_lock_irq(&keypad->lock); > keypad->scan_pending = false; > - enable_row_irqs(keypad); > + if (keypad->stopped == false) > + enable_row_irqs(keypad); > spin_unlock_irq(&keypad->lock); > } > > @@ -202,14 +203,16 @@ static int matrix_keypad_start(struct input_dev *dev) > { > struct matrix_keypad *keypad = input_get_drvdata(dev); > > + spin_lock_irq(&keypad->lock); > keypad->stopped = false; > - mb(); > > /* > * Schedule an immediate key scan to capture current key state; > * columns will be activated and IRQs be enabled after the scan. > */ > - schedule_delayed_work(&keypad->work, 0); > + if (keypad->scan_pending == false) > + schedule_delayed_work(&keypad->work, 0); > + spin_unlock_irq(&keypad->lock); > > return 0; > } > @@ -218,14 +221,17 @@ static void matrix_keypad_stop(struct input_dev *dev) > { > struct matrix_keypad *keypad = input_get_drvdata(dev); > > + spin_lock_irq(&keypad->lock); > keypad->stopped = true; > - mb(); > - flush_work(&keypad->work.work); > /* > * matrix_keypad_scan() will leave IRQs enabled; > * we should disable them now. > */ > - disable_row_irqs(keypad); > + if (keypad->scan_pending == false) > + disable_row_irqs(keypad); > + spin_unlock_irq(&keypad->lock); > + > + flush_work(&keypad->work.work); > } Hum, I think we should use spin_lock_irqsave/spin_lock_irqrestore instead to be on the safe side. I don't see how we could guarantee that irqs is allways enabled when calling spin_lock_irq(). > > #ifdef CONFIG_PM_SLEEP > -- > 2.14.3 Best regards Marcus Folkesson >
At 2018-02-03 21:44:50, "Marcus Folkesson" <marcus.folkesson@gmail.com> wrote: >> diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c >> index 1f316d66e6f7..13fe51824637 100644 >> --- a/drivers/input/keyboard/matrix_keypad.c >> +++ b/drivers/input/keyboard/matrix_keypad.c >> @@ -169,7 +169,8 @@ static void matrix_keypad_scan(struct work_struct *work) >> /* Enable IRQs again */ >> spin_lock_irq(&keypad->lock); >> keypad->scan_pending = false; >> - enable_row_irqs(keypad); >> + if (keypad->stopped == false) >> + enable_row_irqs(keypad); >> spin_unlock_irq(&keypad->lock); >> } >> >> @@ -202,14 +203,16 @@ static int matrix_keypad_start(struct input_dev *dev) >> { >> struct matrix_keypad *keypad = input_get_drvdata(dev); >> >> + spin_lock_irq(&keypad->lock); >> keypad->stopped = false; >> - mb(); >> >> /* >> * Schedule an immediate key scan to capture current key state; >> * columns will be activated and IRQs be enabled after the scan. >> */ >> - schedule_delayed_work(&keypad->work, 0); >> + if (keypad->scan_pending == false) >> + schedule_delayed_work(&keypad->work, 0); >> + spin_unlock_irq(&keypad->lock); >> >> return 0; >> } >> @@ -218,14 +221,17 @@ static void matrix_keypad_stop(struct input_dev *dev) >> { >> struct matrix_keypad *keypad = input_get_drvdata(dev); >> >> + spin_lock_irq(&keypad->lock); >> keypad->stopped = true; >> - mb(); >> - flush_work(&keypad->work.work); >> /* >> * matrix_keypad_scan() will leave IRQs enabled; >> * we should disable them now. >> */ >> - disable_row_irqs(keypad); >> + if (keypad->scan_pending == false) >> + disable_row_irqs(keypad); >> + spin_unlock_irq(&keypad->lock); >> + >> + flush_work(&keypad->work.work); >> } > > >Hum, I think we should use spin_lock_irqsave/spin_lock_irqrestore >instead to be on the safe side. >I don't see how we could guarantee that irqs is allways enabled when >calling spin_lock_irq(). spin_lock_irq and spin_unlock_irq are called in matrix_keypad_stop and matrix_keypad_start which are in suspend and resume, they run in process context, matrix_keypad_scan runs in worker which is in process context also.
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c index 1f316d66e6f7..13fe51824637 100644 --- a/drivers/input/keyboard/matrix_keypad.c +++ b/drivers/input/keyboard/matrix_keypad.c @@ -169,7 +169,8 @@ static void matrix_keypad_scan(struct work_struct *work) /* Enable IRQs again */ spin_lock_irq(&keypad->lock); keypad->scan_pending = false; - enable_row_irqs(keypad); + if (keypad->stopped == false) + enable_row_irqs(keypad); spin_unlock_irq(&keypad->lock); } @@ -202,14 +203,16 @@ static int matrix_keypad_start(struct input_dev *dev) { struct matrix_keypad *keypad = input_get_drvdata(dev); + spin_lock_irq(&keypad->lock); keypad->stopped = false; - mb(); /* * Schedule an immediate key scan to capture current key state; * columns will be activated and IRQs be enabled after the scan. */ - schedule_delayed_work(&keypad->work, 0); + if (keypad->scan_pending == false) + schedule_delayed_work(&keypad->work, 0); + spin_unlock_irq(&keypad->lock); return 0; } @@ -218,14 +221,17 @@ static void matrix_keypad_stop(struct input_dev *dev) { struct matrix_keypad *keypad = input_get_drvdata(dev); + spin_lock_irq(&keypad->lock); keypad->stopped = true; - mb(); - flush_work(&keypad->work.work); /* * matrix_keypad_scan() will leave IRQs enabled; * we should disable them now. */ - disable_row_irqs(keypad); + if (keypad->scan_pending == false) + disable_row_irqs(keypad); + spin_unlock_irq(&keypad->lock); + + flush_work(&keypad->work.work); } #ifdef CONFIG_PM_SLEEP