Hi Michael,
Another comment.
On Tue, Jun 15, 2021 at 04:28:05AM +0300, Laurent Pinchart wrote:
> 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>
> > ---
> > 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;
>
> While at it, you could s/__u8/u8/ as this header isn't used by
> userspace.
>
> > + 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;
>
> Never negative, you can make it an unsigned int.
>
> > +
> > /* 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;
>
> struct usb_composite_dev *cdev = video->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>
>
> Alphabetical order please.
Why is this header needed ? I can't see anything below related to it.
> > #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;
> > + }
>
> Blank line here please.
>
> > + if (video->ureq[i].req_buffer) {
> > + kfree(video->ureq[i].req_buffer);
> > + video->ureq[i].req_buffer = NULL;
> > + }
> > }
>
> Here too.
>
> > + 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;
>
> return -ENOMEM;
>
> would be more readable (I had to check the value of ret to review this
> patch).
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> > +
> > + 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);
--
Regards,
Laurent Pinchart
