6.6-stable review patch. If anyone has any objections, please let me know.
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From: Hans Verkuil hverkuil-cisco@xs4all.nl
[ Upstream commit 3f1faa154a4316b1b585a25394697504b3c24e98 ]
The old (now removed) videobuf framework had an optional vbi hack where the sequence number of the frame counter was copied in the last 4 bytes of the buffer. This hack was active only for the read() interface (so not for streaming I/O), and it was enabled by bttv. This allowed applications that used read() for the VBI data to match it with the corresponding video frame.
When bttv was converted to vb2 this hack was forgotten, but some old applications rely on this.
So add this back, but this time in the bttv driver rather than in the vb2 framework.
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Fixes: b7ec3212a73a ("media: bttv: convert to vb2") Tested-by: Dr. David Alan Gilbert dave@treblig.org Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/pci/bt8xx/bttv-driver.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c index 8e8c9dada67a..49a3dd70ec0f 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -2772,6 +2772,27 @@ bttv_irq_wakeup_vbi(struct bttv *btv, struct bttv_buffer *wakeup, return; wakeup->vbuf.vb2_buf.timestamp = ktime_get_ns(); wakeup->vbuf.sequence = btv->field_count >> 1; + + /* + * Ugly hack for backwards compatibility. + * Some applications expect that the last 4 bytes of + * the VBI data contains the sequence number. + * + * This makes it possible to associate the VBI data + * with the video frame if you use read() to get the + * VBI data. + */ + if (vb2_fileio_is_active(wakeup->vbuf.vb2_buf.vb2_queue)) { + u32 *vaddr = vb2_plane_vaddr(&wakeup->vbuf.vb2_buf, 0); + unsigned long size = + vb2_get_plane_payload(&wakeup->vbuf.vb2_buf, 0) / 4; + + if (vaddr && size) { + vaddr += size - 1; + *vaddr = wakeup->vbuf.sequence; + } + } + vb2_buffer_done(&wakeup->vbuf.vb2_buf, state); if (btv->field_count == 0) btor(BT848_INT_VSYNC, BT848_INT_MASK);