Laurent, Dan, On 24/01/2023 23:35, Michael Grzeschik wrote: > Gentle Ping! Can one of you look at this series? I see that Dan was added as UVC Gadget maintainer earlier this year, so perhaps Dan can look at this? And also other UVC Gadget patches from Michael: https://patchwork.linuxtv.org/project/linux-media/list/?submitter=545 Patchwork is messy: think several of the patches in that list are either superseded or are already merged, but the status was never updated. Regards, Hans > > On Fri, Nov 25, 2022 at 04:34:50PM +0100, Michael Grzeschik wrote: >> When calling uvc_video_encode_isoc_sg the function is preparing the sg payload >> by setting the sglist pointers of the videobuffer for the request. The usb >> gadget driver then is parsing the sg list and uses each sg entry to send in one >> urb to the host. Because of the unrelated buffer of the uvc header that buffer >> has to be send separately in an extra sg entry. >> >> When it comes to transfers with an limited payload (e.g. the maximum of 3kB for >> high-speed) this extra payload handling is not justified. A simple memcpy of >> the header and payload is usually faster and does not come with that extra >> runtime overhead. >> >> This patch is changing the uvc_video_encode_isoc_sg encode function only to be >> used for super speed gadgets. >> >> Cc: stable <stable@xxxxxxxxxx> >> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx> >> >> --- >> v1 -> v2: - left the sg assignment in uvc_buffer_sg under the test for use_sg >> - rephrased the commit message >> >> drivers/usb/gadget/function/uvc_queue.c | 3 +-- >> drivers/usb/gadget/function/uvc_video.c | 9 +++++++-- >> 2 files changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c >> index 0aa3d7e1f3cc32..0abb1763faf1b6 100644 >> --- a/drivers/usb/gadget/function/uvc_queue.c >> +++ b/drivers/usb/gadget/function/uvc_queue.c >> @@ -87,9 +87,8 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb) >> if (queue->use_sg) { >> buf->sgt = vb2_dma_sg_plane_desc(vb, 0); >> buf->sg = buf->sgt->sgl; >> - } else { >> - buf->mem = vb2_plane_vaddr(vb, 0); >> } >> + buf->mem = vb2_plane_vaddr(vb, 0); >> buf->length = vb2_plane_size(vb, 0); >> if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) >> buf->bytesused = 0; >> diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c >> index dd1c6b2ca7c6f3..b6ea600b011185 100644 >> --- a/drivers/usb/gadget/function/uvc_video.c >> +++ b/drivers/usb/gadget/function/uvc_video.c >> @@ -459,6 +459,9 @@ static void uvcg_video_pump(struct work_struct *work) >> */ >> int uvcg_video_enable(struct uvc_video *video, int enable) >> { >> + struct uvc_device *uvc = video->uvc; >> + struct usb_composite_dev *cdev = uvc->func.config->cdev; >> + struct usb_gadget *gadget = cdev->gadget; >> unsigned int i; >> int ret; >> >> @@ -490,9 +493,11 @@ int uvcg_video_enable(struct uvc_video *video, int enable) >> if (video->max_payload_size) { >> video->encode = uvc_video_encode_bulk; >> video->payload_size = 0; >> - } else >> - video->encode = video->queue.use_sg ? >> + } else { >> + video->encode = (video->queue.use_sg && >> + !(gadget->speed <= USB_SPEED_HIGH)) ? >> uvc_video_encode_isoc_sg : uvc_video_encode_isoc; >> + } >> >> video->req_int_count = 0; >> >> -- >> 2.30.2 >> >
