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> --- 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) { -- 2.5.5 -- 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
