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.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
drivers/media/rc/st_rc.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c
index d2efd7b2c3bc..c855b177103c 100644
--- a/drivers/media/rc/st_rc.c
+++ b/drivers/media/rc/st_rc.c
@@ -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);
- status = readl(dev->rx_base + IRB_RX_STATUS);
+ /* 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);
--
2.14.3
