At 2018-02-03 21:44:50, "Marcus Folkesson" <[email protected]> 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.
