Hi Laurent,
On 06/11/2018 23:21, Laurent Pinchart wrote:
> Hi Kieran,
>
> Thank you for the patch.
>
> On Tuesday, 6 November 2018 23:27:20 EET Kieran Bingham wrote:
>> From: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
>>
>> A new iterator is available for processing UVC URB structures. This
>> simplifies the processing of the internal stream data.
>>
>> Convert the manual loop iterators to the new helper, adding an index
>> helper to keep the existing debug print.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
>>
>> ---
>> This patch converts to using the iterator which for most hunks makes
>> sense. The only one with uncertainty is in uvc_alloc_urb_buffers() where
>> the loop index is used to determine if all the buffers were successfully
>> allocated.
>>
>> As the loop index is not incremented by the loops, we can obtain the
>> buffer index - but then we are offset and out-by-one.
>>
>> Adjusting this in the code is fine - but at that point it feels like
>> it's not adding much value. I've left that hunk in for this patch - but
>> that part could be reverted if desired - unless anyone has a better
>> rework of the buffer check?
>>
>> drivers/media/usb/uvc/uvc_video.c | 51 ++++++++++++++++----------------
>> drivers/media/usb/uvc/uvcvideo.h | 3 ++-
>> 2 files changed, 29 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/media/usb/uvc/uvc_video.c
>> b/drivers/media/usb/uvc/uvc_video.c index 020022e6ade4..f6e5db7ea50e 100644
>> --- a/drivers/media/usb/uvc/uvc_video.c
>> +++ b/drivers/media/usb/uvc/uvc_video.c
>> @@ -1556,20 +1556,19 @@ static void uvc_video_complete(struct urb *urb)
>> */
>> static void uvc_free_urb_buffers(struct uvc_streaming *stream)
>> {
>> - unsigned int i;
>> + struct uvc_urb *uvc_urb;
>>
>> - for (i = 0; i < UVC_URBS; ++i) {
>> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
>> + for_each_uvc_urb(uvc_urb, stream) {
>> + if (!uvc_urb->buffer)
>> + continue;
>>
>> - if (uvc_urb->buffer) {
>> #ifndef CONFIG_DMA_NONCOHERENT
>> - usb_free_coherent(stream->dev->udev, stream->urb_size,
>> - uvc_urb->buffer, uvc_urb->dma);
>> + usb_free_coherent(stream->dev->udev, stream->urb_size,
>> + uvc_urb->buffer, uvc_urb->dma);
>> #else
>> - kfree(uvc_urb->buffer);
>> + kfree(uvc_urb->buffer);
>> #endif
>> - uvc_urb->buffer = NULL;
>> - }
>> + uvc_urb->buffer = NULL;
>> }
>>
>> stream->urb_size = 0;
>> @@ -1589,8 +1588,9 @@ static void uvc_free_urb_buffers(struct uvc_streaming
>> *stream) static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
>> unsigned int size, unsigned int psize, gfp_t gfp_flags)
>> {
>> + struct uvc_urb *uvc_urb;
>> unsigned int npackets;
>> - unsigned int i;
>> + unsigned int i = 0;
>>
>> /* Buffers are already allocated, bail out. */
>> if (stream->urb_size)
>> @@ -1605,8 +1605,12 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming
>> *stream,
>>
>> /* Retry allocations until one succeed. */
>> for (; npackets > 1; npackets /= 2) {
>> - for (i = 0; i < UVC_URBS; ++i) {
>> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
>> + for_each_uvc_urb(uvc_urb, stream) {
>> + /*
>> + * Track how many URBs we allocate, adding one to the
>> + * index to account for our zero index.
>> + */
>> + i = uvc_urb_index(uvc_urb) + 1;
>
> That's a bit ugly indeed, I think we could keep the existing loop;
I do agree, as stated I left it in for 'completeness' of the patch. But
I don't think it adds value here.
Will remove.
>> stream->urb_size = psize * npackets;
>> #ifndef CONFIG_DMA_NONCOHERENT
>> @@ -1700,7 +1704,8 @@ static int uvc_init_video_isoc(struct uvc_streaming
>> *stream, struct usb_host_endpoint *ep, gfp_t gfp_flags)
>> {
>> struct urb *urb;
>> - unsigned int npackets, i, j;
>> + struct uvc_urb *uvc_urb;
>> + unsigned int npackets, j;
>
> j without i seems weird, could you rename it ?
Sure. Done
>
>> u16 psize;
>> u32 size;
>>
>> @@ -1713,9 +1718,7 @@ static int uvc_init_video_isoc(struct uvc_streaming
>> *stream,
>>
>> size = npackets * psize;
>>
>> - for (i = 0; i < UVC_URBS; ++i) {
>> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
>> -
>> + for_each_uvc_urb(uvc_urb, stream) {
>> urb = usb_alloc_urb(npackets, gfp_flags);
>> if (urb == NULL) {
>> uvc_video_stop(stream, 1);
>> @@ -1757,7 +1760,8 @@ static int uvc_init_video_bulk(struct uvc_streaming
>> *stream, struct usb_host_endpoint *ep, gfp_t gfp_flags)
>> {
>> struct urb *urb;
>> - unsigned int npackets, pipe, i;
>> + struct uvc_urb *uvc_urb;
>> + unsigned int npackets, pipe;
>> u16 psize;
>> u32 size;
>>
>> @@ -1781,9 +1785,7 @@ static int uvc_init_video_bulk(struct uvc_streaming
>> *stream, if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
>> size = 0;
>>
>> - for (i = 0; i < UVC_URBS; ++i) {
>> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
>> -
>> + for_each_uvc_urb(uvc_urb, stream) {
>> urb = usb_alloc_urb(0, gfp_flags);
>> if (urb == NULL) {
>> uvc_video_stop(stream, 1);
>> @@ -1810,6 +1812,7 @@ static int uvc_video_start(struct uvc_streaming
>> *stream, gfp_t gfp_flags) {
>> struct usb_interface *intf = stream->intf;
>> struct usb_host_endpoint *ep;
>> + struct uvc_urb *uvc_urb;
>> unsigned int i;
>> int ret;
>>
>> @@ -1887,13 +1890,11 @@ static int uvc_video_start(struct uvc_streaming
>> *stream, gfp_t gfp_flags) return ret;
>>
>> /* Submit the URBs. */
>> - for (i = 0; i < UVC_URBS; ++i) {
>> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
>> -
>> + for_each_uvc_urb(uvc_urb, stream) {
>> ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
>> if (ret < 0) {
>> - uvc_printk(KERN_ERR, "Failed to submit URB %u "
>> - "(%d).\n", i, ret);
>> + uvc_printk(KERN_ERR, "Failed to submit URB %u (%d).\n",
>> + uvc_urb_index(uvc_urb), ret);
>> uvc_video_stop(stream, 1);
>> return ret;
>> }
>> diff --git a/drivers/media/usb/uvc/uvcvideo.h
>> b/drivers/media/usb/uvc/uvcvideo.h index c0a120496a1f..6a0f1b59356c 100644
>> --- a/drivers/media/usb/uvc/uvcvideo.h
>> +++ b/drivers/media/usb/uvc/uvcvideo.h
>> @@ -617,6 +617,9 @@ struct uvc_streaming {
>> (uvc_urb) < &(uvc_streaming)->uvc_urb[UVC_URBS]; \
>> ++(uvc_urb))
>>
>> +#define uvc_urb_index(uvc_urb) \
>> + (unsigned int)((uvc_urb) - (&(uvc_urb)->stream->uvc_urb[0]))
>> +
>> struct uvc_device_info {
>> u32 quirks;
>> u32 meta_format;
>
--
Regards
--
Kieran
