| Message ID | 1388664474-1710039-9-git-send-email-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/02/2014 01:07 PM, Arnd Bergmann wrote: > interruptible_sleep_on is racy and going away. In the arv driver that > race has probably never caused problems since it would require a whole > video frame to be captured before the read function has a chance to > go to sleep, but using wait_event_interruptible lets us kill off the > old interface. In order to do this, we have to slightly adapt the > meaning of the ar->start_capture field to distinguish between not having > started a frame and having completed it. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Cc: Mauro Carvalho Chehab <m.chehab@samsung.com> > Cc: linux-media@vger.kernel.org > --- > drivers/media/platform/arv.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/platform/arv.c b/drivers/media/platform/arv.c > index e346d32d..32f6d70 100644 > --- a/drivers/media/platform/arv.c > +++ b/drivers/media/platform/arv.c > @@ -307,11 +307,11 @@ static ssize_t ar_read(struct file *file, char *buf, size_t count, loff_t *ppos) > /* > * Okay, kick AR LSI to invoke an interrupt > */ > - ar->start_capture = 0; > + ar->start_capture = -1; start_capture is defined as an unsigned. Can you make a new patch that changes the type of start_capture to int? Otherwise it looks fine. Regards, Hans > ar_outl(arvcr1 | ARVCR1_HIEN, ARVCR1); > local_irq_restore(flags); > /* .... AR interrupts .... */ > - interruptible_sleep_on(&ar->wait); > + wait_event_interruptible(ar->wait, ar->start_capture == 0); > if (signal_pending(current)) { > printk(KERN_ERR "arv: interrupted while get frame data.\n"); > ret = -EINTR; > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/17/2014 11:51 AM, Hans Verkuil wrote: > On 01/02/2014 01:07 PM, Arnd Bergmann wrote: >> interruptible_sleep_on is racy and going away. In the arv driver that >> race has probably never caused problems since it would require a whole >> video frame to be captured before the read function has a chance to >> go to sleep, but using wait_event_interruptible lets us kill off the >> old interface. In order to do this, we have to slightly adapt the >> meaning of the ar->start_capture field to distinguish between not having >> started a frame and having completed it. >> >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> Cc: Mauro Carvalho Chehab <m.chehab@samsung.com> >> Cc: linux-media@vger.kernel.org >> --- >> drivers/media/platform/arv.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/media/platform/arv.c b/drivers/media/platform/arv.c >> index e346d32d..32f6d70 100644 >> --- a/drivers/media/platform/arv.c >> +++ b/drivers/media/platform/arv.c >> @@ -307,11 +307,11 @@ static ssize_t ar_read(struct file *file, char *buf, size_t count, loff_t *ppos) >> /* >> * Okay, kick AR LSI to invoke an interrupt >> */ >> - ar->start_capture = 0; >> + ar->start_capture = -1; > > start_capture is defined as an unsigned. Can you make a new patch that changes > the type of start_capture to int? > > Otherwise it looks fine. ping! Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday 07 February 2014, Hans Verkuil wrote: > On 01/17/2014 11:51 AM, Hans Verkuil wrote: > >> diff --git a/drivers/media/platform/arv.c b/drivers/media/platform/arv.c > >> index e346d32d..32f6d70 100644 > >> --- a/drivers/media/platform/arv.c > >> +++ b/drivers/media/platform/arv.c > >> @@ -307,11 +307,11 @@ static ssize_t ar_read(struct file *file, char *buf, size_t count, loff_t *ppos) > >> /* > >> * Okay, kick AR LSI to invoke an interrupt > >> */ > >> - ar->start_capture = 0; > >> + ar->start_capture = -1; > > > > start_capture is defined as an unsigned. Can you make a new patch that changes > > the type of start_capture to int? > > > > Otherwise it looks fine. Sorry for the delay. I've updated the patch now and will send it out today with the other remaining ones. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/platform/arv.c b/drivers/media/platform/arv.c index e346d32d..32f6d70 100644 --- a/drivers/media/platform/arv.c +++ b/drivers/media/platform/arv.c @@ -307,11 +307,11 @@ static ssize_t ar_read(struct file *file, char *buf, size_t count, loff_t *ppos) /* * Okay, kick AR LSI to invoke an interrupt */ - ar->start_capture = 0; + ar->start_capture = -1; ar_outl(arvcr1 | ARVCR1_HIEN, ARVCR1); local_irq_restore(flags); /* .... AR interrupts .... */ - interruptible_sleep_on(&ar->wait); + wait_event_interruptible(ar->wait, ar->start_capture == 0); if (signal_pending(current)) { printk(KERN_ERR "arv: interrupted while get frame data.\n"); ret = -EINTR;
interruptible_sleep_on is racy and going away. In the arv driver that race has probably never caused problems since it would require a whole video frame to be captured before the read function has a chance to go to sleep, but using wait_event_interruptible lets us kill off the old interface. In order to do this, we have to slightly adapt the meaning of the ar->start_capture field to distinguish between not having started a frame and having completed it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Mauro Carvalho Chehab <m.chehab@samsung.com> Cc: linux-media@vger.kernel.org --- drivers/media/platform/arv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)