Hi Robert,
I assume, the next iteration of your patches won't contain a local copy of
the SG splitting code.
On Wed, 29 Jul 2015, Robert Jarzmik wrote:
> Convert pxa_camera to dmaengine. This removes all DMA registers
> manipulation in favor of the more generic dmaengine API.
>
> The functional level should be the same as before. The biggest change is
> in the videobuf_sg_splice() function, which splits a videobuf-dma into
> several scatterlists for 3 planes captures (Y, U, V).
>
> Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
> ---
> Since v1: Guennadi's fixes
> dma tasklet functions prototypes change (trivial move)
> Since v2: sglist cut revamped with Guennadi's comments
> ---
> drivers/media/platform/soc_camera/pxa_camera.c | 492 ++++++++++++++-----------
> 1 file changed, 267 insertions(+), 225 deletions(-)
>
> diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c
> index cdfb93aaee43..030ed7413bba 100644
> --- a/drivers/media/platform/soc_camera/pxa_camera.c
> +++ b/drivers/media/platform/soc_camera/pxa_camera.c
[snip]
> @@ -806,28 +824,41 @@ static void pxa_camera_dma_irq(int channel, struct pxa_camera_dev *pcdev,
> buf = container_of(vb, struct pxa_buffer, vb);
> WARN_ON(buf->inwork || list_empty(&vb->queue));
>
> - dev_dbg(dev, "%s channel=%d %s%s(vb=0x%p) dma.desc=%x\n",
> - __func__, channel, status & DCSR_STARTINTR ? "SOF " : "",
> - status & DCSR_ENDINTR ? "EOF " : "", vb, DDADR(channel));
> -
> - if (status & DCSR_ENDINTR) {
> - /*
> - * It's normal if the last frame creates an overrun, as there
> - * are no more DMA descriptors to fetch from QCI fifos
> - */
> - if (camera_status & overrun &&
> - !list_is_last(pcdev->capture.next, &pcdev->capture)) {
> - dev_dbg(dev, "FIFO overrun! CISR: %x\n",
> - camera_status);
> - pxa_camera_stop_capture(pcdev);
> - pxa_camera_start_capture(pcdev);
> - goto out;
> - }
> - buf->active_dma &= ~act_dma;
> - if (!buf->active_dma) {
> - pxa_camera_wakeup(pcdev, vb, buf);
> - pxa_camera_check_link_miss(pcdev);
> - }
> + /*
> + * It's normal if the last frame creates an overrun, as there
> + * are no more DMA descriptors to fetch from QCI fifos
> + */
> + switch (act_dma) {
> + case DMA_U:
> + chan = 1;
> + break;
> + case DMA_V:
> + chan = 2;
> + break;
> + default:
> + chan = 0;
> + break;
> + }
> + last_buf = list_entry(pcdev->capture.prev,
> + struct pxa_buffer, vb.queue);
You can use list_last_entry()
> + last_status = dma_async_is_tx_complete(pcdev->dma_chans[chan],
> + last_buf->cookie[chan],
> + NULL, &last_issued);
> + if (camera_status & overrun &&
> + last_status != DMA_COMPLETE) {
> + dev_dbg(dev, "FIFO overrun! CISR: %x\n",
> + camera_status);
> + pxa_camera_stop_capture(pcdev);
> + list_for_each_entry(buf, &pcdev->capture, vb.queue)
> + pxa_dma_add_tail_buf(pcdev, buf);
Why have you added this loop? Is it a bug in the current implementation or
is it only needed with the switch to dmaengine?
> + pxa_camera_start_capture(pcdev);
> + goto out;
> + }
> + buf->active_dma &= ~act_dma;
> + if (!buf->active_dma) {
> + pxa_camera_wakeup(pcdev, vb, buf);
> + pxa_camera_check_link_miss(pcdev, last_buf->cookie[chan],
> + last_issued);
> }
>
> out:
> @@ -1014,10 +1045,7 @@ static void pxa_camera_clock_stop(struct soc_camera_host *ici)
> __raw_writel(0x3ff, pcdev->base + CICR0);
>
> /* Stop DMA engine */
> - DCSR(pcdev->dma_chans[0]) = 0;
> - DCSR(pcdev->dma_chans[1]) = 0;
> - DCSR(pcdev->dma_chans[2]) = 0;
> -
> + pxa_dma_stop_channels(pcdev);
> pxa_camera_deactivate(pcdev);
> }
>
>
Thanks
Guennadi
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