Input: omap-keypad - use disable_irq_nosync() in irq handler (0f751719) · Commits · 戴 / test

disable_irq() waits for all running handlers to complete before returning. As such, if it's used to disable an interrupt from that interrupt's handler it will deadlock. This replaces the dangerous instances with the _nosync() variant which doesn't have this problem. Signed-off-by:

Ben Nizette <bn@niasdigital.com> Signed-off-by:

Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/omap-keypad.c

+14 −2

Original line number	Diff line number	Diff line
		@@ -100,8 +100,20 @@ static irqreturn_t omap_kp_interrupt(int irq, void *dev_id)
		/* disable keyboard interrupt and schedule for handling */
		if (cpu_is_omap24xx()) {
		int i;
		for (i = 0; i < omap_kp->rows; i++)
		disable_irq(gpio_to_irq(row_gpios[i]));

		for (i = 0; i < omap_kp->rows; i++) {
		int gpio_irq = gpio_to_irq(row_gpios[i]);
		/*
		* The interrupt which we're currently handling should
		* be disabled _nosync() to avoid deadlocks waiting
		* for this handler to complete. All others should
		* be disabled the regular way for SMP safety.
		*/
		if (gpio_irq == irq)
		disable_irq_nosync(gpio_irq);
		else
		disable_irq(gpio_irq);
		}
		} else
		/* disable keyboard interrupt and schedule for handling */
		omap_writew(1, OMAP_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);

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