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Subject[PATCH RFC] media: radio: handle timeouts
Date
Add handling for timeout case.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
---
Some error state/error information seems be get lost int the current code.
(line-numbers are from 3.19.0-rc7.

Assume that on line 827 core->write succeeds but the following
wait_for_completion_timeout times out and the radio->irq_received condition
is not satisfied resulting in goto out;

827 r = core->write(core, WL1273_TUNER_MODE_SET, TUNER_MODE_AUTO_SEEK);
828 if (r)
829 goto out;
830
831 wait_for_completion_timeout(&radio->busy, msecs_to_jiffies(1000));
832 if (!(radio->irq_received & WL1273_BL_EVENT))
833 goto out;


A similar situation is at line 955 - 859 where a tiemout could occure
and the reported value would be the success value from core->write.

852 reinit_completion(&radio->busy);
853 dev_dbg(radio->dev, "%s: BUSY\n", __func__);
854
855 r = core->write(core, WL1273_TUNER_MODE_SET, TUNER_MODE_AUTO_SEEK);
856 if (r)
857 goto out;
858
859 wait_for_completion_timeout(&radio->busy, msecs_to_jiffies(1000)

the problem is that the value of r now is the "success" value from core->write
and any timeout and/or failure to detect the expected interrupt is not
reported in

860 out:
861 dev_dbg(radio->dev, "%s: Err: %d\n", __func__, r);
862 return r;

Should the wait_for_completion_timeout not report the timeout event by setting
r to -ETIMEOUT ? respectively use if (!(radio->irq_received & WL1273_BL_EVENT))
to check and set -ETIMEOUT there ?

Comparing this with wl1273_fm_set_tx_freq - the below patch might be suitable
way to handle timeout - but this needs a review by someone who knows the
details of the driver - so this is really just a guess.

Patch was only compile tested with x86_64_defconfig + CONFIG_MEDIA_SUPPORT=m
CONFIG_MEDIA_CAMERA_SUPPORT=y, CONFIG_V4L_PLATFORM_DRIVERS=y,
CONFIG_MEDIA_RADIO_SUPPORT=y, RADIO_ADAPTER=y, CONFIG_RADIO_WL1273=m

Patch is against 3.19.0-rc7 (localversion-next is -next-20150204)

drivers/media/radio/radio-wl1273.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/media/radio/radio-wl1273.c b/drivers/media/radio/radio-wl1273.c
index 571c7f6..6830523 100644
--- a/drivers/media/radio/radio-wl1273.c
+++ b/drivers/media/radio/radio-wl1273.c
@@ -828,9 +828,12 @@ static int wl1273_fm_set_seek(struct wl1273_device *radio,
if (r)
goto out;

+ /* wait for the FR IRQ */
wait_for_completion_timeout(&radio->busy, msecs_to_jiffies(1000));
- if (!(radio->irq_received & WL1273_BL_EVENT))
+ if (!(radio->irq_received & WL1273_BL_EVENT)) {
+ r = -ETIMEDOUT;
goto out;
+ }

radio->irq_received &= ~WL1273_BL_EVENT;

@@ -856,7 +859,9 @@ static int wl1273_fm_set_seek(struct wl1273_device *radio,
if (r)
goto out;

- wait_for_completion_timeout(&radio->busy, msecs_to_jiffies(1000));
+ /* wait for the FR IRQ */
+ if (!wait_for_completion_timeout(&radio->busy, msecs_to_jiffies(1000)))
+ r = -ETIMEDOUT;
out:
dev_dbg(radio->dev, "%s: Err: %d\n", __func__, r);
return r;
--
1.7.10.4


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