On Sat, May 13, 2006, Dyks, Axel (XL) wrote: > "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> > > --- linux-2.6.16.orig/drivers/media/dvb/cinergyT2/cinergyT2.c 2006-03-20 06:53:29.000000000 +0100 > +++ linux-2.6.16/drivers/media/dvb/cinergyT2/cinergyT2.c 2006-05-13 01:15:24.000000000 +0200 > @@ -540,15 +540,18 @@ > { > struct dvb_device *dvbdev = file->private_data; > struct cinergyt2 *cinergyt2 = dvbdev->priv; > + unsigned int mask = 0; > > if (cinergyt2->disconnect_pending || down_interruptible(&cinergyt2->sem)) > return -ERESTARTSYS; > > poll_wait(file, &cinergyt2->poll_wq, wait); > > + if (cinergyt2->pending_fe_events != 0) mask |= (POLLIN | POLLRDNORM | POLLPRI); Please *never* do this. Better: if (cinergyt2->pending_fe_events != 0) mask |= (POLLIN | POLLRDNORM | POLLPRI); > + > up(&cinergyt2->sem); > > - return (POLLIN | POLLRDNORM | POLLPRI); > + return mask; > } BTW, the sem stuff has been replaced by mutex. However, I wonder why that sem/mutex is used at all. What data does it protect? *cinergyt2 won't be released before the fd is closed (if it would, cinergyt2->sem would also be invalid)... Johannes _______________________________________________ linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
