[media] cx23885: convert to vb2

As usual, this patch is very large due to the fact that half a vb2 conversion
isn't possible. And since this affects 417, alsa, core, dvb, vbi and video the
changes are all over.

What made this more difficult was the peculiar way the risc program was setup.
The driver allowed for running out of buffers in which case the DMA would stop
and restart when the next buffer was queued. There was also a complicated
timeout system for when buffers weren't filled. This was replaced by a much
simpler scheme where there is always one buffer around and the DMA will just
cycle that buffer until a new buffer is queued. In that case the previous
buffer will be chained to the new buffer. An interrupt is generated at the
start of the new buffer telling the driver that the previous buffer can be
passed on to userspace.

Much simpler and more robust. The old code seems to be copied from the
cx88 driver. But it didn't fit the vb2 ops very well and replacing it with
the new scheme made the code easier to understand. Not to mention that this
patch removes 600 lines of code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/media/pci/cx23885/cx23885-alsa.c b/drivers/media/pci/cx23885/cx23885-alsa.c
index c17e4740d47c..1b162ee8c8c6 100644
--- a/drivers/media/pci/cx23885/cx23885-alsa.c
+++ b/drivers/media/pci/cx23885/cx23885-alsa.c
@@ -389,6 +389,7 @@ static int snd_cx23885_hw_params(struct snd_pcm_substream *substream,
 		return -ENOMEM;
 
 	buf->bpl = chip->period_size;
+	chip->buf = buf;
 
 	ret = cx23885_alsa_dma_init(chip,
 			(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
@@ -409,8 +410,6 @@ static int snd_cx23885_hw_params(struct snd_pcm_substream *substream,
 	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
 	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
 
-	chip->buf = buf;
-
 	substream->runtime->dma_area = chip->buf->vaddr;
 	substream->runtime->dma_bytes = chip->dma_size;
 	substream->runtime->dma_addr = 0;
@@ -419,6 +418,7 @@ static int snd_cx23885_hw_params(struct snd_pcm_substream *substream,
 
 error:
 	kfree(buf);
+	chip->buf = NULL;
 	return ret;
 }