[linux-dvb] Re: [PATCH] dvb/cinergyT2: Fix cinergyt2_poll() to allow for non-blocking IO on the frontend device

[Dyks, Axel (XL)]

Hi,

meanwhile I've received positive feedback in the vlc forum.
So I'm wondering, if there is a chance for the patch to
be applied to the "v4l-dvb" sources ...

Axel

Dyks, Axel (XL) wrote:
> Dyks, Axel (XL) wrote:
> 
>>fixed indention and "diff"-ed against "v4l-dvb.git"
>>
>>"cinergyt2_poll()" shouldn't return (POLLIN | POLLRDNORM | POLLPRI) when
>>there are no pending events. User space programs that do non-bocking IO
>>using "select()" and/or "poll()" would otherwise produce high system load.
>>See http://forum.videolan.org/viewtopic.php?t=20529 for details.
>>
>>Signed-off-by: Axel Dyks <xl at xlsigned.net>  
>>
>>diff --git a/drivers/media/dvb/cinergyT2/cinergyT2.c b/drivers/media/dvb/cinergyT2/cinergyT2.c
>>index 9325d03..9d77ef0 100644
>>--- a/drivers/media/dvb/cinergyT2/cinergyT2.c
>>+++ b/drivers/media/dvb/cinergyT2/cinergyT2.c
>>@@ -544,15 +544,19 @@ static unsigned int cinergyt2_poll (stru
>> {
>> 	struct dvb_device *dvbdev = file->private_data;
>> 	struct cinergyt2 *cinergyt2 = dvbdev->priv;
>>+	unsigned int mask = 0;
>> 
>> 	if (cinergyt2->disconnect_pending || mutex_lock_interruptible(&cinergyt2->sem))
>> 		return -ERESTARTSYS;
>> 
>> 	poll_wait(file, &cinergyt2->poll_wq, wait);
>> 
>>+	if (cinergyt2->pending_fe_events != 0)
>>+		mask |= (POLLIN | POLLRDNORM | POLLPRI);
>>+
>> 	mutex_unlock(&cinergyt2->sem);
>> 
>>-	return (POLLIN | POLLRDNORM | POLLPRI);
>>+	return mask;
>> }
>>