[PATCH v2 0/7] usb: gadget: uvc: smaller fixes for stability

[PATCH v2 0/7] usb: gadget: uvc: smaller fixes for stability

[Michael Grzeschik]

This series improves the uvc video gadget overal stability and code
quality. Including a fix for the configfs udc callbacks.

Michael Grzeschik (6):
  usb: gadget: uvc: consistently use define for headerlen
  usb: gadget: uvc: test if ep->desc is valid on ep_queue
  usb: gadget: uvc: only schedule stream in streaming state
  usb: gadget: uvc: only pump video data if necessary
  usb: gadget: uvc: ensure the vdev is unset
  usb: gadget: udc: ensure the gadget is still available

Michael Tretter (1):
  usb: gadget: uvc: rename function to be more consistent

 drivers/usb/gadget/composite.c          |  4 ++--
 drivers/usb/gadget/function/f_uvc.c     |  7 ++++---
 drivers/usb/gadget/function/uvc_v4l2.c  |  3 ++-
 drivers/usb/gadget/function/uvc_video.c | 23 ++++++++++++++++-------
 drivers/usb/gadget/udc/core.c           |  3 +++
 5 files changed, 27 insertions(+), 13 deletions(-)

-- 
2.30.2

[PATCH v2 1/7] usb: gadget: uvc: consistently use define for headerlen

[Michael Grzeschik]

The uvc request headerlen of 2 was defined as UVCG_REQUEST_HEADER_LEN
in commit e81e7f9a0eb9 ("usb: gadget: uvc: add scatter gather support").
We missed to use it consistently. This patch fixes that.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by

 drivers/usb/gadget/function/uvc_video.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index b4a763e5f70e1..da93b46df464d 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -302,7 +302,9 @@ uvc_video_alloc_requests(struct uvc_video *video)
 		list_add_tail(&video->ureq[i].req->list, &video->req_free);
 		/* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
 		sg_alloc_table(&video->ureq[i].sgt,
-			       DIV_ROUND_UP(req_size - 2, PAGE_SIZE) + 2,
+			       DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN,
+					    PAGE_SIZE) +
+			       UVCG_REQUEST_HEADER_LEN,
 			       GFP_KERNEL);
 	}
 
-- 
2.30.2

[PATCH v2 2/7] usb: gadget: uvc: rename function to be more consistent

[Michael Grzeschik]

From: Michael Tretter <m.tretter@pengutronix.de>

When enabling info debugging for the uvc gadget, the bind and unbind
infos use different formats. Change the unbind to visually match the
bind.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by

 drivers/usb/gadget/function/f_uvc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 9d87c0fb8f92e..1e93ab5c0c88d 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -884,12 +884,12 @@ static void uvc_free(struct usb_function *f)
 	kfree(uvc);
 }
 
-static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
+static void uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct usb_composite_dev *cdev = c->cdev;
 	struct uvc_device *uvc = to_uvc(f);
 
-	uvcg_info(f, "%s\n", __func__);
+	uvcg_info(f, "%s()\n", __func__);
 
 	device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
 	video_unregister_device(&uvc->vdev);
@@ -943,7 +943,7 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
 	/* Register the function. */
 	uvc->func.name = "uvc";
 	uvc->func.bind = uvc_function_bind;
-	uvc->func.unbind = uvc_unbind;
+	uvc->func.unbind = uvc_function_unbind;
 	uvc->func.get_alt = uvc_function_get_alt;
 	uvc->func.set_alt = uvc_function_set_alt;
 	uvc->func.disable = uvc_function_disable;
-- 
2.30.2

[PATCH v2 3/7] usb: gadget: uvc: test if ep->desc is valid on ep_queue

[Michael Grzeschik]

The reason that the ep_queue has failed could be a disabled endpoint.
In that case it is not guaranteed that the ep->desc is still valid.
This patch adds an check for NULL.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by
    - fixed typo in commit message

 drivers/usb/gadget/function/uvc_video.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index da93b46df464d..cdfd3726a86ae 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -199,9 +199,11 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
 		uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
 			 ret);
 
-		/* Isochronous endpoints can't be halted. */
-		if (usb_endpoint_xfer_bulk(video->ep->desc))
-			usb_ep_set_halt(video->ep);
+		if (video->ep->desc) {
+			/* Isochronous endpoints can't be halted. */
+			if (usb_endpoint_xfer_bulk(video->ep->desc))
+				usb_ep_set_halt(video->ep);
+		}
 	}
 
 	return ret;
-- 
2.30.2

[PATCH v2 4/7] usb: gadget: uvc: only schedule stream in streaming state

[Michael Grzeschik]

This patch ensures that the video pump thread will only be scheduled if
the uvc is really in streaming state. This way the worker will not have
to run on an empty queue.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by

 drivers/usb/gadget/function/uvc_v4l2.c  | 3 ++-
 drivers/usb/gadget/function/uvc_video.c | 4 +++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index 4ca89eab61590..67922b1355e69 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -169,7 +169,8 @@ uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 	if (ret < 0)
 		return ret;
 
-	schedule_work(&video->pump);
+	if (uvc->state == UVC_STATE_STREAMING)
+		schedule_work(&video->pump);
 
 	return ret;
 }
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index cdfd3726a86ae..ccee35177411d 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -215,6 +215,7 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 	struct uvc_request *ureq = req->context;
 	struct uvc_video *video = ureq->video;
 	struct uvc_video_queue *queue = &video->queue;
+	struct uvc_device *uvc = video->uvc;
 	unsigned long flags;
 
 	switch (req->status) {
@@ -237,7 +238,8 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 	list_add_tail(&req->list, &video->req_free);
 	spin_unlock_irqrestore(&video->req_lock, flags);
 
-	schedule_work(&video->pump);
+	if (uvc->state == UVC_STATE_STREAMING)
+		schedule_work(&video->pump);
 }
 
 static int
-- 
2.30.2

[PATCH v2 5/7] usb: gadget: uvc: only pump video data if necessary

[Michael Grzeschik]

If the streaming endpoint is not enabled, the worker has nothing to do.
In the case it still got enqueued, this patch ensueres that it will bail
out without handling any data.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by

 drivers/usb/gadget/function/uvc_video.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index ccee35177411d..152647495fa61 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -335,12 +335,12 @@ static void uvcg_video_pump(struct work_struct *work)
 {
 	struct uvc_video *video = container_of(work, struct uvc_video, pump);
 	struct uvc_video_queue *queue = &video->queue;
-	struct usb_request *req;
+	struct usb_request *req = NULL;
 	struct uvc_buffer *buf;
 	unsigned long flags;
 	int ret;
 
-	while (1) {
+	while (video->ep->enabled) {
 		/* Retrieve the first available USB request, protected by the
 		 * request lock.
 		 */
@@ -390,6 +390,9 @@ static void uvcg_video_pump(struct work_struct *work)
 		video->req_int_count++;
 	}
 
+	if (!req)
+		return;
+
 	spin_lock_irqsave(&video->req_lock, flags);
 	list_add_tail(&req->list, &video->req_free);
 	spin_unlock_irqrestore(&video->req_lock, flags);
-- 
2.30.2

[PATCH v2 6/7] usb: gadget: uvc: ensure the vdev is unset

[Michael Grzeschik]

Since the uvc video device is created on demand, we have to ensure
that the struct is always zeroed. Otherwise the previous settings
might collide with the new values.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - added reviewed by
    - fixed patch description

 drivers/usb/gadget/function/f_uvc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 1e93ab5c0c88d..b3279ba357331 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -417,6 +417,7 @@ uvc_register_video(struct uvc_device *uvc)
 	int ret;
 
 	/* TODO reference counting. */
+	memset(&uvc->vdev, 0, sizeof(struct video_device));
 	uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
 	uvc->vdev.v4l2_dev->dev = &cdev->gadget->dev;
 	uvc->vdev.fops = &uvc_v4l2_fops;
-- 
2.30.2

[PATCH v2 7/7] usb: gadget: udc: ensure the gadget is still available

[Michael Grzeschik]

It is possible that the configfs gadget layer will be calling the unbind
functions of all gadget functions on gadget_dev_desc_UDC_store and
cleaned up the cdev structures pointer to the gadget. This will not
prevent the usage of the usb_function_de/activate functions.

f_obex and f_uvc are the candidates to still call the functions with no
valid gadget set. This patch prevents the usage of the gadget if it was
already unset.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v2: - no changes

 drivers/usb/gadget/composite.c | 4 ++--
 drivers/usb/gadget/udc/core.c  | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 504c1cbc255d1..1b4cd01e2ae13 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -393,7 +393,7 @@ int usb_function_deactivate(struct usb_function *function)
 
 	spin_lock_irqsave(&cdev->lock, flags);
 
-	if (cdev->deactivations == 0) {
+	if (cdev->deactivations == 0 && cdev->gadget) {
 		spin_unlock_irqrestore(&cdev->lock, flags);
 		status = usb_gadget_deactivate(cdev->gadget);
 		spin_lock_irqsave(&cdev->lock, flags);
@@ -428,7 +428,7 @@ int usb_function_activate(struct usb_function *function)
 		status = -EINVAL;
 	else {
 		cdev->deactivations--;
-		if (cdev->deactivations == 0) {
+		if (cdev->deactivations == 0 && cdev->gadget) {
 			spin_unlock_irqrestore(&cdev->lock, flags);
 			status = usb_gadget_activate(cdev->gadget);
 			spin_lock_irqsave(&cdev->lock, flags);
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 14fdf918ecfeb..52964d0e26fa6 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -756,6 +756,9 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
 {
 	int ret = 0;
 
+	if (!gadget)
+		return ret;
+
 	if (gadget->deactivated)
 		goto out;
 
-- 
2.30.2

Re: [PATCH v2 0/7] usb: gadget: uvc: smaller fixes for stability

[Laurent Pinchart]

Hi Michael,

On Sun, Oct 03, 2021 at 10:29:32PM +0200, Michael Grzeschik wrote:
> This series improves the uvc video gadget overal stability and code
> quality. Including a fix for the configfs udc callbacks.

I've only noticed v2 after reviewing v1, sorry about that. I think all
comments still apply though.

> Michael Grzeschik (6):
>   usb: gadget: uvc: consistently use define for headerlen
>   usb: gadget: uvc: test if ep->desc is valid on ep_queue
>   usb: gadget: uvc: only schedule stream in streaming state
>   usb: gadget: uvc: only pump video data if necessary
>   usb: gadget: uvc: ensure the vdev is unset
>   usb: gadget: udc: ensure the gadget is still available
> 
> Michael Tretter (1):
>   usb: gadget: uvc: rename function to be more consistent
> 
>  drivers/usb/gadget/composite.c          |  4 ++--
>  drivers/usb/gadget/function/f_uvc.c     |  7 ++++---
>  drivers/usb/gadget/function/uvc_v4l2.c  |  3 ++-
>  drivers/usb/gadget/function/uvc_video.c | 23 ++++++++++++++++-------
>  drivers/usb/gadget/udc/core.c           |  3 +++
>  5 files changed, 27 insertions(+), 13 deletions(-)
> 

-- 
Regards,

Laurent Pinchart