Re: [PATCH, RFC 08/30] [media] arv: fix sleep_on race

[Hans Verkuil]

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@xxxxxxxx>
>> Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
>> Cc: linux-media@xxxxxxxxxxxxxxx
>> ---
>>  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
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