Le vendredi 06 mai 2016 à 18:11 -0400, Javier Martinez Canillas a écrit : > From: ayaka <ayaka@xxxxxxxxxxx> > > User-space applications can use the VIDIOC_REQBUFS ioctl to determine > if a > memory mapped, user pointer or DMABUF based I/O is supported by the > driver. > > So a set of VIDIOC_REQBUFS ioctl calls will be made with count 0 and > then > the real VIDIOC_REQBUFS call with count == n. But for count 0, the > driver > not only frees the buffer but also closes the MFC instance and > s5p_mfc_ctx > state is set to MFCINST_FREE. > > The VIDIOC_REQBUFS handler for the output device checks if the > s5p_mfc_ctx > state is set to MFCINST_INIT (which happens on an VIDIOC_S_FMT) and > fails > otherwise. So after a VIDIOC_REQBUFS(n), future VIDIOC_REQBUFS(n) > calls > will fails unless a VIDIOC_S_FMT ioctl calls happens before the > reqbufs. > > But applications may first set the format and then attempt to > determine > the I/O methods supported by the driver (for example Gstramer does > it) so > the state won't be set to MFCINST_INIT again and VIDIOC_REQBUFS will > fail. > > To avoid this issue, only free the buffers on VIDIOC_REQBUFS(0) but > don't > close the MFC instance to allow future VIDIOC_REQBUFS(n) calls to > succeed. > > Signed-off-by: ayaka <ayaka@xxxxxxxxxxx> > [javier: Rewrote changelog to explain the problem more detailed] > Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> I just tested this change, it also seems correct. Acked-by: Nicolas Dufresne <nicolas@xxxxxxxxxxxxx> > > --- > Hello, > > This is a resend of a patch posted by Ayaka some time ago [0]. > Without $SUBJECT, trying to decode a video using Gstramer fails > on an Exynos5422 Odroid XU4 board with following error message: > > $ gst-launch-1.0 filesrc location=test.mov ! qtdemux ! h264parse ! > v4l2video0dec ! videoconvert ! autovideosink > > Setting pipeline to PAUSED ... > Pipeline is PREROLLING ... > [ 3947.114756] vidioc_reqbufs:576: Only V4L2_MEMORY_MAP is supported > [ 3947.114771] vidioc_reqbufs:576: Only V4L2_MEMORY_MAP is supported > [ 3947.114903] reqbufs_output:484: Reqbufs called in an invalid state > [ 3947.114913] reqbufs_output:510: Failed allocating buffers for > OUTPUT queue > ERROR: from element > /GstPipeline:pipeline0/v4l2video0dec:v4l2video0dec0: Failed to > allocate required memory. > Additional debug info: > gstv4l2videodec.c(575): gst_v4l2_video_dec_handle_frame (): > /GstPipeline:pipeline0/v4l2video0dec:v4l2video0dec0: > Buffer pool activation failed > ERROR: pipeline doesn't want to preroll. > Setting pipeline to NULL ... > Freeing pipeline ... > > [0]: https://patchwork.linuxtv.org/patch/32794/ > > Best regards, > Javier > > drivers/media/platform/s5p-mfc/s5p_mfc_dec.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c > b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c > index f2d6376ce618..8b9467de2d6a 100644 > --- a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c > +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c > @@ -474,7 +474,6 @@ static int reqbufs_output(struct s5p_mfc_dev > *dev, struct s5p_mfc_ctx *ctx, > ret = vb2_reqbufs(&ctx->vq_src, reqbufs); > if (ret) > goto out; > - s5p_mfc_close_mfc_inst(dev, ctx); > ctx->src_bufs_cnt = 0; > ctx->output_state = QUEUE_FREE; > } else if (ctx->output_state == QUEUE_FREE) {
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