Hi Mauro, On Tuesday 16 September 2014 02:05:38 Mauro Carvalho Chehab wrote: > This is an automatic generated email to let you know that the following > patch were queued at the http://git.linuxtv.org/media_tree.git tree: > > Subject: [media] BZ#84401: Revert "[media] v4l: vb2: Don't return POLLERR > during transient buffer underruns" Author: Mauro Carvalho Chehab > <m.chehab@xxxxxxxxxxx> > Date: Mon Sep 15 20:58:01 2014 -0300 > > This reverts commit 9241650d62f79a3da01f1d5e8ebd195083330b75. > > The commit 9241650d62f7 was meant to solve an issue with Gstreamer > version 0.10 with libv4l 1.2, where a fixup patch for DQBUF exposed > a bad behavior ag Gstreamer. > > It does that by returning POLERR if VB2 is not streaming. > > However, it broke VBI userspace support on alevt and mtt (and maybe > other VBI apps), as they rely on the old behavior. > > Due to that, we need to roll back and restore the previous behavior. > > It means that there are still some potential regressions by reverting it, > but those are known to occur only if: > - libv4l is version 1.2 or upper (due to DQBUF fixup); > - Gstreamer version 1.2 or before are being used, as this bug > got fixed on Gstreamer 1.4. > > As both libv4l 1.2 and Gstreamer version 1.4 were released about the same > time, and the fix went only on Kernel 3.16 and were not backported to > stable, it is very unlikely that reverting it would cause much harm. > > For more details, see: > https://bugzilla.kernel.org/show_bug.cgi?id=84401 > > Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx> > Cc: Pawel Osciak <pawel@xxxxxxxxxx> > Cc: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> > Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> > > drivers/media/v4l2-core/videobuf2-core.c | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > --- > > http://git.linuxtv.org/media_tree.git?a=commitdiff;h=e0857d1d1af8478b33e63db > b22bb2160a807d868 > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c > b/drivers/media/v4l2-core/videobuf2-core.c index 7e6aff6..7387821 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -2583,10 +2583,10 @@ unsigned int vb2_poll(struct vb2_queue *q, struct > file *file, poll_table *wait) } > > /* > - * There is nothing to wait for if no buffer has been queued and the > - * queue isn't streaming, or if the error flag is set. > + * There is nothing to wait for if no buffer has been queued > + * or if the error flag is set. > */ > - if ((list_empty(&q->queued_list) && !vb2_is_streaming(q)) || q->error) > + if ((list_empty(&q->queued_list) || q->error) This has probably not been compile-tested. > return res | POLLERR; > > /* -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
