Commit ee2d243d authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

media: st_rc: Don't stay on an IRQ handler forever 



As warned by smatch:
	drivers/media/rc/st_rc.c:110 st_rc_rx_interrupt() warn: this loop depends on readl() succeeding

If something goes wrong at readl(), the logic will stay there
inside an IRQ code forever. This is not the nicest thing to
do :-)

So, add a timeout there, preventing staying inside the IRQ
for more than 10ms.

Acked-by: default avatarPatrice Chotard <patrice.chotard@st.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent ca33f8f6

drivers/media/rc/st_rc.c

+10 −6
Original line number Diff line number Diff line
@@ -96,19 +96,24 @@ static void st_rc_send_lirc_timeout(struct rc_dev *rdev) 


static irqreturn_t st_rc_rx_interrupt(int irq, void *data)

{

	unsigned long timeout;

	unsigned int symbol, mark = 0;

	struct st_rc_device *dev = data;

	int last_symbol = 0;

	u32 status;

	u32 status, int_status;

	DEFINE_IR_RAW_EVENT(ev);



	if (dev->irq_wake)

		pm_wakeup_event(dev->dev, 0);



	/* FIXME: is 10ms good enough ? */

	timeout = jiffies +  msecs_to_jiffies(10);

	do {

		status  = readl(dev->rx_base + IRB_RX_STATUS);

		if (!(status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)))

			break;



	while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {

		u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);

		int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);

		if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {

			/* discard the entire collection in case of errors!  */

			ir_raw_event_reset(dev->rdev);
@@ -148,8 +153,7 @@ static irqreturn_t st_rc_rx_interrupt(int irq, void *data) 


		}

		last_symbol = 0;

		status  = readl(dev->rx_base + IRB_RX_STATUS);

	}

	} while (time_is_after_jiffies(timeout));



	writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);

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