Hi Michael,
On Mon, May 31, 2021 at 12:30:39AM +0200, Michael Grzeschik wrote:
> While sending bigger images is possible with USB_SPEED_SUPER it is
> better to use more isochronous requests in flight. This patch makes the
> number uvc_num_requests dynamic by changing it depending on the gadget
> speed.
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
Looks good to me.
Reviewed-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> ---
> v1 -> v2: - fixed null pointer dereference in uvc_video_free_requests
>
> drivers/usb/gadget/function/uvc.h | 11 +++--
> drivers/usb/gadget/function/uvc_queue.c | 7 ++++
> drivers/usb/gadget/function/uvc_video.c | 56 +++++++++++++++----------
> 3 files changed, 48 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
> index 23ee25383c1f7..83b9e945944e8 100644
> --- a/drivers/usb/gadget/function/uvc.h
> +++ b/drivers/usb/gadget/function/uvc.h
> @@ -65,13 +65,17 @@ extern unsigned int uvc_gadget_trace_param;
> * Driver specific constants
> */
>
> -#define UVC_NUM_REQUESTS 4
> #define UVC_MAX_REQUEST_SIZE 64
> #define UVC_MAX_EVENTS 4
>
> /* ------------------------------------------------------------------------
> * Structures
> */
> +struct uvc_request {
> + struct usb_request *req;
> + __u8 *req_buffer;
> + struct uvc_video *video;
> +};
>
> struct uvc_video {
> struct uvc_device *uvc;
> @@ -87,10 +91,11 @@ struct uvc_video {
> unsigned int imagesize;
> struct mutex mutex; /* protects frame parameters */
>
> + int uvc_num_requests;
> +
> /* Requests */
> unsigned int req_size;
> - struct usb_request *req[UVC_NUM_REQUESTS];
> - __u8 *req_buffer[UVC_NUM_REQUESTS];
> + struct uvc_request *ureq;
> struct list_head req_free;
> spinlock_t req_lock;
>
> diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
> index 61e2c94cc0b0c..dcd71304d521c 100644
> --- a/drivers/usb/gadget/function/uvc_queue.c
> +++ b/drivers/usb/gadget/function/uvc_queue.c
> @@ -43,6 +43,8 @@ static int uvc_queue_setup(struct vb2_queue *vq,
> {
> struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> struct uvc_video *video = container_of(queue, struct uvc_video, queue);
> + struct uvc_device *uvc = video->uvc;
> + struct usb_composite_dev *cdev = uvc->func.config->cdev;
>
> if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
> *nbuffers = UVC_MAX_VIDEO_BUFFERS;
> @@ -51,6 +53,11 @@ static int uvc_queue_setup(struct vb2_queue *vq,
>
> sizes[0] = video->imagesize;
>
> + if (cdev->gadget->speed < USB_SPEED_SUPER)
> + video->uvc_num_requests = 4;
> + else
> + video->uvc_num_requests = 64;
> +
> return 0;
> }
>
> diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
> index 633e23d58d868..57840083dfdda 100644
> --- a/drivers/usb/gadget/function/uvc_video.c
> +++ b/drivers/usb/gadget/function/uvc_video.c
> @@ -11,6 +11,7 @@
> #include <linux/errno.h>
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> +#include <linux/module.h>
> #include <linux/usb/video.h>
>
> #include <media/v4l2-dev.h>
> @@ -145,7 +146,8 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
> static void
> uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
> {
> - struct uvc_video *video = req->context;
> + struct uvc_request *ureq = req->context;
> + struct uvc_video *video = ureq->video;
> struct uvc_video_queue *queue = &video->queue;
> unsigned long flags;
>
> @@ -177,16 +179,19 @@ uvc_video_free_requests(struct uvc_video *video)
> {
> unsigned int i;
>
> - for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
> - if (video->req[i]) {
> - usb_ep_free_request(video->ep, video->req[i]);
> - video->req[i] = NULL;
> - }
> -
> - if (video->req_buffer[i]) {
> - kfree(video->req_buffer[i]);
> - video->req_buffer[i] = NULL;
> + if (video->ureq) {
> + for (i = 0; i < video->uvc_num_requests; ++i) {
> + if (video->ureq[i].req) {
> + usb_ep_free_request(video->ep, video->ureq[i].req);
> + video->ureq[i].req = NULL;
> + }
> + if (video->ureq[i].req_buffer) {
> + kfree(video->ureq[i].req_buffer);
> + video->ureq[i].req_buffer = NULL;
> + }
> }
> + kfree(video->ureq);
> + video->ureq = NULL;
> }
>
> INIT_LIST_HEAD(&video->req_free);
> @@ -207,21 +212,26 @@ uvc_video_alloc_requests(struct uvc_video *video)
> * max_t(unsigned int, video->ep->maxburst, 1)
> * (video->ep->mult);
>
> - for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
> - video->req_buffer[i] = kmalloc(req_size, GFP_KERNEL);
> - if (video->req_buffer[i] == NULL)
> + video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL);
> + if (video->ureq == NULL)
> + return ret;
> +
> + for (i = 0; i < video->uvc_num_requests; ++i) {
> + video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL);
> + if (video->ureq[i].req_buffer == NULL)
> goto error;
>
> - video->req[i] = usb_ep_alloc_request(video->ep, GFP_KERNEL);
> - if (video->req[i] == NULL)
> + video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL);
> + if (video->ureq[i].req == NULL)
> goto error;
>
> - video->req[i]->buf = video->req_buffer[i];
> - video->req[i]->length = 0;
> - video->req[i]->complete = uvc_video_complete;
> - video->req[i]->context = video;
> + video->ureq[i].req->buf = video->ureq[i].req_buffer;
> + video->ureq[i].req->length = 0;
> + video->ureq[i].req->complete = uvc_video_complete;
> + video->ureq[i].req->context = &video->ureq[i];
> + video->ureq[i].video = video;
>
> - list_add_tail(&video->req[i]->list, &video->req_free);
> + list_add_tail(&video->ureq[i].req->list, &video->req_free);
> }
>
> video->req_size = req_size;
> @@ -312,9 +322,9 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
> cancel_work_sync(&video->pump);
> uvcg_queue_cancel(&video->queue, 0);
>
> - for (i = 0; i < UVC_NUM_REQUESTS; ++i)
> - if (video->req[i])
> - usb_ep_dequeue(video->ep, video->req[i]);
> + for (i = 0; i < video->uvc_num_requests; ++i)
> + if (video->ureq && video->ureq[i].req)
> + usb_ep_dequeue(video->ep, video->ureq[i].req);
>
> uvc_video_free_requests(video);
> uvcg_queue_enable(&video->queue, 0);
> --
> 2.29.2
>
