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

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Hi,

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@xxxxxxxxxxxx>  

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;
 }
 
 

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