diff options
| author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2018-04-12 06:32:18 -0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2018-04-17 05:50:05 -0400 |
| commit | ee2d243d6beea21e79631fa3442e92ad0fa11a6a (patch) | |
| tree | 1fb02a176ae653ffccd798831558174a44336d90 | |
| parent | ca33f8f61a6e4376cc006b713a353e7200e66f59 (diff) | |
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: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
| -rw-r--r-- | drivers/media/rc/st_rc.c | 16 |
1 files 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); |