From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1DD52BE622; Fri, 11 Jul 2025 15:53:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752249220; cv=none; b=Fib8zpcoFW7TvVpWTm6OS22ooYUStojX8AiBS9HoOBtgzLd6tUhUvv4nDNtysTTOEWy+kZdBUbHb4E5kmDIAl65U2iwKR2TRoCMRFOe/HXLoP1VcLF+prTsDq6aoOc+yT0QVs51rf5Vl6t4ibo/TxBUmM6EaTzyz6v7d7v45rKs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752249220; c=relaxed/simple; bh=nyiF00MPXx6ylE57yYw9nF6gq3H56h633Sk9ezskolo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gSpl8OwXZ+8JZEGKBBvWzT3G1bhBUMl5Qk1yle2WBEBmlMk/tapsG4H0Q0R68knc0AJd1sOlXYksB3NJxFjEZ7HrCc4Ng2xP4kgKcuEB/RjciCv/hBylxnq4i05ZGUlama2LR2NFx0zW49jNttrk1irrpdefSccYQCzUXhFwVw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=jWT4zqrD; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="jWT4zqrD" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id C465AD77; Fri, 11 Jul 2025 17:53:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1752249186; bh=nyiF00MPXx6ylE57yYw9nF6gq3H56h633Sk9ezskolo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jWT4zqrDqjkm382mcEBFz/3zq29J73El8VqC9uACLpBCKHdyuo4htaaDUITfcW0ym fUWbynwYZvwdcFI/f96MwsJcwE0AGbsmtmpoB8jKlmzuN4apMqGeoU2HEnlT1b1mqT xVOIDX39CCD7V2owyHWuArmoGgoW8YqscNFU5vpI= Date: Fri, 11 Jul 2025 18:53:04 +0300 From: Laurent Pinchart To: Ricardo Ribalda Cc: Hans de Goede , Hans Verkuil , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Hans de Goede , Hans Verkuil Subject: Re: [PATCH v2 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers Message-ID: <20250711155304.GA28533@pendragon.ideasonboard.com> References: <20250602-uvc-fop-v2-0-508a293eae81@chromium.org> <20250602-uvc-fop-v2-2-508a293eae81@chromium.org> <20250602183126.GI23515@pendragon.ideasonboard.com> <20250603084926.GB3879@pendragon.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hi Ricardo, On Tue, Jun 03, 2025 at 12:07:09PM +0200, Ricardo Ribalda wrote: > On Tue, 3 Jun 2025 at 10:49, Laurent Pinchart wrote: > > On Mon, Jun 02, 2025 at 09:53:09PM +0200, Ricardo Ribalda wrote: > > > On Mon, 2 Jun 2025 at 20:31, Laurent Pinchart wrote: > > > > On Mon, Jun 02, 2025 at 12:59:03PM +0000, Ricardo Ribalda wrote: > > > > > From: Hans Verkuil > > > > > > > > > > When uvc was written the vb2 ioctl and file operation helpers didn't exist. > > > > > > > > > > This patch switches uvc over to those helpers, which removes a lot of > > > > > boilerplate code and simplifies VIDIOC_G/S_PRIORITY handling > > > > > > > > How does it simplify VIDIOC_[GS]_PRIORITY handling ? The only thing this > > > > patch does related to priority is replace the per-chain priority > > > > handling with a per-device (as in uvc_device) priority, as the default > > > > is to use the prio state from v4l2_device. I think this is actually > > > > incorrect, a UVC device can have multiple independent streaming > > > > interfaces, so the priority ioctls should no operate on a device-wide > > > > prio state. Am I missing something ? > > > > > > You are correct. > > > The uvcvideo is the only driver that does not use the prio state from > > > v4l2_device and it makes v4l2-core a bit more complicated. > > > > > > I have not seen a real use of VIDIOC_[GS]_PRIORITY, so being a bit > > > incorrect in favor of simplicity is probably a good trade-off. > > > Anyway it is an easy change to split into a different patch, we can > > > have the discussion about prio there. > > > > > > > > and allows us > > > > > to drop the 'privileges' scheme, since that's now handled inside the vb2 > > > > > helpers. > > > > > > > > That part is correct. The driver implements a privilege-management > > > > system similar to the vb2_queue_is_busy() checks in the vb2 ioctl > > > > handlers, as the ioctl handlers didn't exist back then. > > > > > > > > Please reword the commit message to make this clearer. If the prio > > > > change is also desired, it should be split in a separate patch. > > > > > > > > > This makes it possible for uvc to fix the v4l2-compliance streaming tests: > > > > > warn: v4l2-test-formats.cpp(1075): Could not set fmt2 > > > > > > > > > > This patch introduces a change on behavior on the uvcdriver to be > > > > > aligned with the rest of the subsystem. Now S_INPUT, S_PARM and > > > > > S_FORMAT do no grant exclusive ownership of the device. > > > > > > > > There are other changes in behaviour worth noting, some small, some > > > > quite substantial. Let's start with the small one: .vidioc_querybuf() > > > > now succeeds when the queue is busy. It seems a check may be missing in > > > > v4l2-compliance for this. > > > > > > Agree, > > > After we land this we can add the check to v4l2-compliance. > > > > > > > The bigger change is related to locking. See below. > > > > > > > > > Reviewed-by: Hans de Goede > > > > > Reviewed-by: Hans Verkuil > > > > > Signed-off-by: Hans Verkuil > > > > > Co-developed-by: Ricardo Ribalda > > > > > Signed-off-by: Ricardo Ribalda > > > > > --- > > > > > drivers/media/usb/uvc/uvc_driver.c | 34 +---- > > > > > drivers/media/usb/uvc/uvc_metadata.c | 8 +- > > > > > drivers/media/usb/uvc/uvc_queue.c | 143 -------------------- > > > > > drivers/media/usb/uvc/uvc_v4l2.c | 251 +++-------------------------------- > > > > > drivers/media/usb/uvc/uvcvideo.h | 37 +----- > > > > > 5 files changed, 30 insertions(+), 443 deletions(-) > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > > > index da24a655ab68cc0957762f2b67387677c22224d1..4eeedab93b90939fc4c925012a18b7d018ade39f 100644 > > > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > > > @@ -1725,7 +1725,6 @@ static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev) > > > > > INIT_LIST_HEAD(&chain->entities); > > > > > mutex_init(&chain->ctrl_mutex); > > > > > chain->dev = dev; > > > > > - v4l2_prio_init(&chain->prio); > > > > > > > > > > return chain; > > > > > } > > > > > @@ -1958,31 +1957,7 @@ static void uvc_unregister_video(struct uvc_device *dev) > > > > > if (!video_is_registered(&stream->vdev)) > > > > > continue; > > > > > > > > > > - /* > > > > > - * For stream->vdev we follow the same logic as: > > > > > - * vb2_video_unregister_device(). > > > > > - */ > > > > > - > > > > > - /* 1. Take a reference to vdev */ > > > > > - get_device(&stream->vdev.dev); > > > > > - > > > > > - /* 2. Ensure that no new ioctls can be called. */ > > > > > - video_unregister_device(&stream->vdev); > > > > > - > > > > > - /* 3. Wait for old ioctls to finish. */ > > > > > - mutex_lock(&stream->mutex); > > > > > - > > > > > - /* 4. Stop streaming. */ > > > > > - uvc_queue_release(&stream->queue); > > > > > - > > > > > - mutex_unlock(&stream->mutex); > > > > > - > > > > > - put_device(&stream->vdev.dev); > > > > > - > > > > > - /* > > > > > - * For stream->meta.vdev we can directly call: > > > > > - * vb2_video_unregister_device(). > > > > > - */ > > > > > + vb2_video_unregister_device(&stream->vdev); > > > > > vb2_video_unregister_device(&stream->meta.vdev); > > > > > > > > > > /* > > > > > @@ -2029,7 +2004,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > > > vdev->fops = fops; > > > > > vdev->ioctl_ops = ioctl_ops; > > > > > vdev->release = uvc_release; > > > > > - vdev->prio = &stream->chain->prio; > > > > > + vdev->queue = &queue->queue; > > > > > + vdev->lock = &queue->mutex; > > > > > > > > This will cause the ioctl handlers to use queue->mutex for all ioctls > > > > (both INFO_FL_QUEUE and !INFO_FL_QUEUE). Locking therefore gets more > > > > coarse, that should be mentioned in the commit message. > > > > > > > > > if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT) > > > > > vdev->vfl_dir = VFL_DIR_TX; > > > > > else > > > > > @@ -2399,8 +2375,8 @@ static int __uvc_resume(struct usb_interface *intf, int reset) > > > > > if (stream->intf == intf) { > > > > > ret = uvc_video_resume(stream, reset); > > > > > if (ret < 0) > > > > > - uvc_queue_streamoff(&stream->queue, > > > > > - stream->queue.queue.type); > > > > > + vb2_streamoff(&stream->queue.queue, > > > > > + stream->queue.queue.type); > > > > > > > > This doesn't take any lock anymore. Can that be a problem ? > > > > > > ack > > > Probably better to keep the same lock pattern as before. I am adding > > > mutex_lock/unlock > > > > > > > > return ret; > > > > > } > > > > > } > > > > > diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c > > > > > index 82de7781f5b6b70c5ba16bcba9e0741231231904..d3aab22f91cea21aefc56409924dfa1451aec914 100644 > > > > > --- a/drivers/media/usb/uvc/uvc_metadata.c > > > > > +++ b/drivers/media/usb/uvc/uvc_metadata.c > > > > > @@ -96,7 +96,7 @@ static int uvc_meta_v4l2_set_format(struct file *file, void *fh, > > > > > */ > > > > > mutex_lock(&stream->mutex); > > > > > > > > Is this lock still needed ? More broadly speaking, what's the remaining > > > > purpose of stream->mutex ? Or perhaps the other way around, shouldn't we > > > > drop queue->mutex, and use stream->mutex everywhere instead ? > > > > > > Good question, this is the first thing that I tried, and there are > > > plenty of nested locking that are wrong: > > > lock(stream->mutex) > > > lock(stream->muex) > > > > > > It is probably fixable, but we can do that as a follow-up patch. > > > > The current locking scheme was designed with two locks, to separate > > locking of the buffer-related ioctls from the other ioctls, the same way > > that the V4L2 core has a video_device lock and a vb2_queue lock. We > > could keep the same design and move to using separate video_device and > > vb2_queue locks, but that's not what this patch does. I'm OK with > > switching to a single lock as I can't provide compelling evidence that > > two locks significantly improve performance (do they ever, or should > > V4L2 drop that ?) with uvcvideo at the moment, but I'd like the locking > > scheme to remain clean and understandable. > > I agree with your goal of having a single lock. The question is how to > reach that goal. > > I think it is easier/better to do it in two steps: > 1) Land this set, where the queue->mutex locks more ioctls than > before, and we keep the stream->mutex > 2) Remove one of the mutex. > > My reasons are: > - You, HdG, HansV and I are familiar with the current change and have > already reviewed it. > - Completely refactoring the locking in the same patch will make the > code more difficult to review. > - There are other patchsets that conflict with this set. > - HansV expressed that he wants this addressed with priority. > - The patch fixes v4l2-compliance. > - The patch simplifies the code. > > I will look into the new locking the same way that I have been looking > into other housekeeping changes in the uvc driver. But I do not > believe that we should block the development for this. I disagree this is best done on top, but I won't block the series for this. I do however expect a new patch series to address the issue, I feel quite uncomfortable leaving the code in its current state as it gives me an impression of an unfinished job that leaves possible bugs behind. > > > > > > > > > > - if (uvc_queue_allocated(&stream->queue)) > > > > > + if (vb2_is_busy(&stream->meta.queue.queue)) > > > > > ret = -EBUSY; > > > > > else > > > > > stream->meta.format = fmt->dataformat; > > > > > @@ -164,12 +164,6 @@ int uvc_meta_register(struct uvc_streaming *stream) > > > > > > > > > > stream->meta.format = V4L2_META_FMT_UVC; > > > > > > > > > > - /* > > > > > - * The video interface queue uses manual locking and thus does not set > > > > > - * the queue pointer. Set it manually here. > > > > > - */ > > > > > - vdev->queue = &queue->queue; > > > > > - > > > > > return uvc_register_video_device(dev, stream, vdev, queue, > > > > > V4L2_BUF_TYPE_META_CAPTURE, > > > > > &uvc_meta_fops, &uvc_meta_ioctl_ops); > > > > > diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c > > > > > index 2ee142621042167c2587b6a6fdd51c1a46d31c11..72c5494dee9f46ff61072e7d293bfaddda40e615 100644 > > > > > --- a/drivers/media/usb/uvc/uvc_queue.c > > > > > +++ b/drivers/media/usb/uvc/uvc_queue.c > > > > > @@ -242,153 +242,10 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type) > > > > > return 0; > > > > > } > > > > > > > > > > -void uvc_queue_release(struct uvc_video_queue *queue) > > > > > -{ > > > > > - mutex_lock(&queue->mutex); > > > > > - vb2_queue_release(&queue->queue); > > > > > - mutex_unlock(&queue->mutex); > > > > > -} > > > > > - > > > > > -/* ----------------------------------------------------------------------------- > > > > > - * V4L2 queue operations > > > > > - */ > > > > > - > > > > > -int uvc_request_buffers(struct uvc_video_queue *queue, > > > > > - struct v4l2_requestbuffers *rb) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_reqbufs(&queue->queue, rb); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret ? ret : rb->count; > > > > > -} > > > > > - > > > > > -int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_querybuf(&queue->queue, buf); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_create_buffers(struct uvc_video_queue *queue, > > > > > - struct v4l2_create_buffers *cb) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_create_bufs(&queue->queue, cb); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_queue_buffer(struct uvc_video_queue *queue, > > > > > - struct media_device *mdev, struct v4l2_buffer *buf) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_qbuf(&queue->queue, mdev, buf); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_export_buffer(struct uvc_video_queue *queue, > > > > > - struct v4l2_exportbuffer *exp) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_expbuf(&queue->queue, exp); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf, > > > > > - int nonblocking) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_dqbuf(&queue->queue, buf, nonblocking); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_streamon(&queue->queue, type); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type) > > > > > -{ > > > > > - int ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_streamoff(&queue->queue, type); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > -int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) > > > > > -{ > > > > > - return vb2_mmap(&queue->queue, vma); > > > > > -} > > > > > - > > > > > -#ifndef CONFIG_MMU > > > > > -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, > > > > > - unsigned long pgoff) > > > > > -{ > > > > > - return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); > > > > > -} > > > > > -#endif > > > > > - > > > > > -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, > > > > > - poll_table *wait) > > > > > -{ > > > > > - __poll_t ret; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - ret = vb2_poll(&queue->queue, file, wait); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return ret; > > > > > -} > > > > > - > > > > > /* ----------------------------------------------------------------------------- > > > > > * > > > > > */ > > > > > > > > > > -/* > > > > > - * Check if buffers have been allocated. > > > > > - */ > > > > > -int uvc_queue_allocated(struct uvc_video_queue *queue) > > > > > -{ > > > > > - int allocated; > > > > > - > > > > > - mutex_lock(&queue->mutex); > > > > > - allocated = vb2_is_busy(&queue->queue); > > > > > - mutex_unlock(&queue->mutex); > > > > > - > > > > > - return allocated; > > > > > -} > > > > > - > > > > > /* > > > > > * Cancel the video buffers queue. > > > > > * > > > > > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c > > > > > index 862b4e34e5b629cf324479a9bb59ebe8784ccd5d..7a5ecbefa32c0a6b74c85d7f77a25b433598471e 100644 > > > > > --- a/drivers/media/usb/uvc/uvc_v4l2.c > > > > > +++ b/drivers/media/usb/uvc/uvc_v4l2.c > > > > > @@ -47,8 +47,6 @@ void uvc_pm_put(struct uvc_device *dev) > > > > > usb_autopm_put_interface(dev->intf); > > > > > } > > > > > > > > > > -static int uvc_acquire_privileges(struct uvc_fh *handle); > > > > > - > > > > > static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain, > > > > > struct uvc_control_mapping *map, > > > > > const struct uvc_xu_control_mapping *xmap) > > > > > @@ -436,10 +434,6 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh, > > > > > const struct uvc_frame *frame; > > > > > int ret; > > > > > > > > > > - ret = uvc_acquire_privileges(handle); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > if (fmt->type != stream->type) > > > > > return -EINVAL; > > > > > > > > > > @@ -448,8 +442,7 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh, > > > > > return ret; > > > > > > > > > > mutex_lock(&stream->mutex); > > > > > - > > > > > - if (uvc_queue_allocated(&stream->queue)) { > > > > > + if (vb2_is_busy(&stream->queue.queue)) { > > > > > ret = -EBUSY; > > > > > goto done; > > > > > } > > > > > @@ -513,10 +506,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh, > > > > > unsigned int i; > > > > > int ret; > > > > > > > > > > - ret = uvc_acquire_privileges(handle); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > if (parm->type != stream->type) > > > > > return -EINVAL; > > > > > > > > > > @@ -593,63 +582,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh, > > > > > return 0; > > > > > } > > > > > > > > > > -/* ------------------------------------------------------------------------ > > > > > - * Privilege management > > > > > - */ > > > > > - > > > > > -/* > > > > > - * Privilege management is the multiple-open implementation basis. The current > > > > > - * implementation is completely transparent for the end-user and doesn't > > > > > - * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls. > > > > > - * Those ioctls enable finer control on the device (by making possible for a > > > > > - * user to request exclusive access to a device), but are not mature yet. > > > > > - * Switching to the V4L2 priority mechanism might be considered in the future > > > > > - * if this situation changes. > > > > > - * > > > > > - * Each open instance of a UVC device can either be in a privileged or > > > > > - * unprivileged state. Only a single instance can be in a privileged state at > > > > > - * a given time. Trying to perform an operation that requires privileges will > > > > > - * automatically acquire the required privileges if possible, or return -EBUSY > > > > > - * otherwise. Privileges are dismissed when closing the instance or when > > > > > - * freeing the video buffers using VIDIOC_REQBUFS. > > > > > - * > > > > > - * Operations that require privileges are: > > > > > - * > > > > > - * - VIDIOC_S_INPUT > > > > > - * - VIDIOC_S_PARM > > > > > - * - VIDIOC_S_FMT > > > > > - * - VIDIOC_CREATE_BUFS > > > > > - * - VIDIOC_REQBUFS > > > > > - */ > > > > > -static int uvc_acquire_privileges(struct uvc_fh *handle) > > > > > -{ > > > > > - /* Always succeed if the handle is already privileged. */ > > > > > - if (handle->state == UVC_HANDLE_ACTIVE) > > > > > - return 0; > > > > > - > > > > > - /* Check if the device already has a privileged handle. */ > > > > > - if (atomic_inc_return(&handle->stream->active) != 1) { > > > > > - atomic_dec(&handle->stream->active); > > > > > - return -EBUSY; > > > > > - } > > > > > - > > > > > - handle->state = UVC_HANDLE_ACTIVE; > > > > > - return 0; > > > > > -} > > > > > - > > > > > -static void uvc_dismiss_privileges(struct uvc_fh *handle) > > > > > -{ > > > > > - if (handle->state == UVC_HANDLE_ACTIVE) > > > > > - atomic_dec(&handle->stream->active); > > > > > - > > > > > - handle->state = UVC_HANDLE_PASSIVE; > > > > > -} > > > > > - > > > > > -static int uvc_has_privileges(struct uvc_fh *handle) > > > > > -{ > > > > > - return handle->state == UVC_HANDLE_ACTIVE; > > > > > -} > > > > > - > > > > > /* ------------------------------------------------------------------------ > > > > > * V4L2 file operations > > > > > */ > > > > > @@ -671,7 +603,6 @@ static int uvc_v4l2_open(struct file *file) > > > > > v4l2_fh_add(&handle->vfh); > > > > > handle->chain = stream->chain; > > > > > handle->stream = stream; > > > > > - handle->state = UVC_HANDLE_PASSIVE; > > > > > file->private_data = handle; > > > > > > > > > > return 0; > > > > > @@ -686,18 +617,11 @@ static int uvc_v4l2_release(struct file *file) > > > > > > > > > > uvc_ctrl_cleanup_fh(handle); > > > > > > > > > > - /* Only free resources if this is a privileged handle. */ > > > > > - if (uvc_has_privileges(handle)) > > > > > - uvc_queue_release(&stream->queue); > > > > > - > > > > > if (handle->is_streaming) > > > > > uvc_pm_put(stream->dev); > > > > > > > > > > /* Release the file handle. */ > > > > > - uvc_dismiss_privileges(handle); > > > > > - v4l2_fh_del(&handle->vfh); > > > > > - v4l2_fh_exit(&handle->vfh); > > > > > - kfree(handle); > > > > > + vb2_fop_release(file); > > > > > file->private_data = NULL; > > > > > > > > You can drop setting private_data to NULL, it's done by > > > > v4l2_fh_release() called by vb2_fop_release(). > > > > > > ack > > > > > > > > > > > > > return 0; > > > > > @@ -753,91 +677,6 @@ static int uvc_ioctl_try_fmt(struct file *file, void *fh, > > > > > return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL); > > > > > } > > > > > > > > > > -static int uvc_ioctl_reqbufs(struct file *file, void *fh, > > > > > - struct v4l2_requestbuffers *rb) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - int ret; > > > > > - > > > > > - ret = uvc_acquire_privileges(handle); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > - mutex_lock(&stream->mutex); > > > > > - ret = uvc_request_buffers(&stream->queue, rb); > > > > > - mutex_unlock(&stream->mutex); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > - if (ret == 0) > > > > > - uvc_dismiss_privileges(handle); > > > > > - > > > > > - return 0; > > > > > -} > > > > > - > > > > > -static int uvc_ioctl_querybuf(struct file *file, void *fh, > > > > > - struct v4l2_buffer *buf) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - return uvc_query_buffer(&stream->queue, buf); > > > > > -} > > > > > - > > > > > -static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - return uvc_queue_buffer(&stream->queue, > > > > > - stream->vdev.v4l2_dev->mdev, buf); > > > > > -} > > > > > - > > > > > -static int uvc_ioctl_expbuf(struct file *file, void *fh, > > > > > - struct v4l2_exportbuffer *exp) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - return uvc_export_buffer(&stream->queue, exp); > > > > > -} > > > > > - > > > > > -static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - return uvc_dequeue_buffer(&stream->queue, buf, > > > > > - file->f_flags & O_NONBLOCK); > > > > > -} > > > > > - > > > > > -static int uvc_ioctl_create_bufs(struct file *file, void *fh, > > > > > - struct v4l2_create_buffers *cb) > > > > > -{ > > > > > - struct uvc_fh *handle = fh; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - int ret; > > > > > - > > > > > - ret = uvc_acquire_privileges(handle); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > - return uvc_create_buffers(&stream->queue, cb); > > > > > -} > > > > > - > > > > > static int uvc_ioctl_streamon(struct file *file, void *fh, > > > > > enum v4l2_buf_type type) > > > > > { > > > > > @@ -845,11 +684,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh, > > > > > struct uvc_streaming *stream = handle->stream; > > > > > int ret; > > > > > > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - guard(mutex)(&stream->mutex); > > > > > - > > > > > if (handle->is_streaming) > > > > > return 0; > > > > > > > > > > @@ -857,7 +691,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh, > > > > > if (ret) > > > > > return ret; > > > > > > > > > > - ret = uvc_queue_streamon(&stream->queue, type); > > > > > + ret = vb2_ioctl_streamon(file, fh, type); > > > > > if (ret) { > > > > > uvc_pm_put(stream->dev); > > > > > return ret; > > > > > @@ -873,13 +707,12 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh, > > > > > { > > > > > struct uvc_fh *handle = fh; > > > > > struct uvc_streaming *stream = handle->stream; > > > > > + int ret; > > > > > > > > > > - if (!uvc_has_privileges(handle)) > > > > > - return -EBUSY; > > > > > - > > > > > - guard(mutex)(&stream->mutex); > > > > > + ret = vb2_ioctl_streamoff(file, fh, type); > > > > > + if (ret) > > > > > + return ret; > > > > > > > > > > - uvc_queue_streamoff(&stream->queue, type); > > > > > if (handle->is_streaming) { > > > > > handle->is_streaming = false; > > > > > uvc_pm_put(stream->dev); > > > > > @@ -962,13 +795,13 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input) > > > > > static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input) > > > > > { > > > > > struct uvc_fh *handle = fh; > > > > > + struct uvc_streaming *stream = handle->stream; > > > > > struct uvc_video_chain *chain = handle->chain; > > > > > u8 *buf; > > > > > int ret; > > > > > > > > > > - ret = uvc_acquire_privileges(handle); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > + if (vb2_is_busy(&stream->queue.queue)) > > > > > + return -EBUSY; > > > > > > > > > > if (chain->selector == NULL || > > > > > (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { > > > > > @@ -1471,50 +1304,6 @@ static long uvc_v4l2_unlocked_ioctl(struct file *file, > > > > > return ret; > > > > > } > > > > > > > > > > -static ssize_t uvc_v4l2_read(struct file *file, char __user *data, > > > > > - size_t count, loff_t *ppos) > > > > > -{ > > > > > - struct uvc_fh *handle = file->private_data; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - uvc_dbg(stream->dev, CALLS, "%s: not implemented\n", __func__); > > > > > - return -EINVAL; > > > > > -} > > > > > - > > > > > -static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma) > > > > > -{ > > > > > - struct uvc_fh *handle = file->private_data; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - uvc_dbg(stream->dev, CALLS, "%s\n", __func__); > > > > > - > > > > > - return uvc_queue_mmap(&stream->queue, vma); > > > > > -} > > > > > - > > > > > -static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait) > > > > > -{ > > > > > - struct uvc_fh *handle = file->private_data; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - uvc_dbg(stream->dev, CALLS, "%s\n", __func__); > > > > > - > > > > > - return uvc_queue_poll(&stream->queue, file, wait); > > > > > -} > > > > > - > > > > > -#ifndef CONFIG_MMU > > > > > -static unsigned long uvc_v4l2_get_unmapped_area(struct file *file, > > > > > - unsigned long addr, unsigned long len, unsigned long pgoff, > > > > > - unsigned long flags) > > > > > -{ > > > > > - struct uvc_fh *handle = file->private_data; > > > > > - struct uvc_streaming *stream = handle->stream; > > > > > - > > > > > - uvc_dbg(stream->dev, CALLS, "%s\n", __func__); > > > > > - > > > > > - return uvc_queue_get_unmapped_area(&stream->queue, pgoff); > > > > > -} > > > > > -#endif > > > > > - > > > > > const struct v4l2_ioctl_ops uvc_ioctl_ops = { > > > > > .vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt, > > > > > .vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt, > > > > > @@ -1527,12 +1316,13 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = { > > > > > .vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt, > > > > > .vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt, > > > > > .vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt, > > > > > - .vidioc_reqbufs = uvc_ioctl_reqbufs, > > > > > - .vidioc_querybuf = uvc_ioctl_querybuf, > > > > > - .vidioc_qbuf = uvc_ioctl_qbuf, > > > > > - .vidioc_expbuf = uvc_ioctl_expbuf, > > > > > - .vidioc_dqbuf = uvc_ioctl_dqbuf, > > > > > - .vidioc_create_bufs = uvc_ioctl_create_bufs, > > > > > + .vidioc_reqbufs = vb2_ioctl_reqbufs, > > > > > + .vidioc_querybuf = vb2_ioctl_querybuf, > > > > > + .vidioc_prepare_buf = vb2_ioctl_prepare_buf, > > > > > + .vidioc_qbuf = vb2_ioctl_qbuf, > > > > > + .vidioc_expbuf = vb2_ioctl_expbuf, > > > > > + .vidioc_dqbuf = vb2_ioctl_dqbuf, > > > > > + .vidioc_create_bufs = vb2_ioctl_create_bufs, > > > > > .vidioc_streamon = uvc_ioctl_streamon, > > > > > .vidioc_streamoff = uvc_ioctl_streamoff, > > > > > .vidioc_enum_input = uvc_ioctl_enum_input, > > > > > @@ -1559,11 +1349,10 @@ const struct v4l2_file_operations uvc_fops = { > > > > > #ifdef CONFIG_COMPAT > > > > > .compat_ioctl32 = uvc_v4l2_compat_ioctl32, > > > > > #endif > > > > > - .read = uvc_v4l2_read, > > > > > - .mmap = uvc_v4l2_mmap, > > > > > - .poll = uvc_v4l2_poll, > > > > > + .mmap = vb2_fop_mmap, > > > > > + .poll = vb2_fop_poll, > > > > > #ifndef CONFIG_MMU > > > > > - .get_unmapped_area = uvc_v4l2_get_unmapped_area, > > > > > + .get_unmapped_area = vb2_fop_get_unmapped_area, > > > > > #endif > > > > > }; > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > > > > > index b9f8eb62ba1d82ea7788cf6c10cc838a429dbc9e..3ddbf065a2cbae40ee48cb06f84ca8f0052990c4 100644 > > > > > --- a/drivers/media/usb/uvc/uvcvideo.h > > > > > +++ b/drivers/media/usb/uvc/uvcvideo.h > > > > > @@ -326,7 +326,10 @@ struct uvc_buffer { > > > > > > > > > > struct uvc_video_queue { > > > > > struct vb2_queue queue; > > > > > - struct mutex mutex; /* Protects queue */ > > > > > + struct mutex mutex; /* > > > > > + * Serializes vb2_queue and > > > > > + * fops > > > > > + */ > > > > > > > > > > unsigned int flags; > > > > > unsigned int buf_used; > > > > > @@ -349,7 +352,6 @@ struct uvc_video_chain { > > > > > * uvc_fh.pending_async_ctrls > > > > > */ > > > > > > > > > > - struct v4l2_prio_state prio; /* V4L2 priority state */ > > > > > u32 caps; /* V4L2 chain-wide caps */ > > > > > u8 ctrl_class_bitmap; /* Bitmap of valid classes */ > > > > > }; > > > > > @@ -619,16 +621,10 @@ struct uvc_device { > > > > > struct uvc_entity *gpio_unit; > > > > > }; > > > > > > > > > > -enum uvc_handle_state { > > > > > - UVC_HANDLE_PASSIVE = 0, > > > > > - UVC_HANDLE_ACTIVE = 1, > > > > > -}; > > > > > - > > > > > struct uvc_fh { > > > > > struct v4l2_fh vfh; > > > > > struct uvc_video_chain *chain; > > > > > struct uvc_streaming *stream; > > > > > - enum uvc_handle_state state; > > > > > unsigned int pending_async_ctrls; > > > > > bool is_streaming; > > > > > }; > > > > > @@ -687,36 +683,11 @@ struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id); > > > > > > > > > > /* Video buffers queue management. */ > > > > > int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type); > > > > > -void uvc_queue_release(struct uvc_video_queue *queue); > > > > > -int uvc_request_buffers(struct uvc_video_queue *queue, > > > > > - struct v4l2_requestbuffers *rb); > > > > > -int uvc_query_buffer(struct uvc_video_queue *queue, > > > > > - struct v4l2_buffer *v4l2_buf); > > > > > -int uvc_create_buffers(struct uvc_video_queue *queue, > > > > > - struct v4l2_create_buffers *v4l2_cb); > > > > > -int uvc_queue_buffer(struct uvc_video_queue *queue, > > > > > - struct media_device *mdev, > > > > > - struct v4l2_buffer *v4l2_buf); > > > > > -int uvc_export_buffer(struct uvc_video_queue *queue, > > > > > - struct v4l2_exportbuffer *exp); > > > > > -int uvc_dequeue_buffer(struct uvc_video_queue *queue, > > > > > - struct v4l2_buffer *v4l2_buf, int nonblocking); > > > > > -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type); > > > > > -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type); > > > > > void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect); > > > > > struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, > > > > > struct uvc_buffer *buf); > > > > > struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue); > > > > > void uvc_queue_buffer_release(struct uvc_buffer *buf); > > > > > -int uvc_queue_mmap(struct uvc_video_queue *queue, > > > > > - struct vm_area_struct *vma); > > > > > -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, > > > > > - poll_table *wait); > > > > > -#ifndef CONFIG_MMU > > > > > -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, > > > > > - unsigned long pgoff); > > > > > -#endif > > > > > -int uvc_queue_allocated(struct uvc_video_queue *queue); > > > > > static inline int uvc_queue_streaming(struct uvc_video_queue *queue) > > > > > { > > > > > return vb2_is_streaming(&queue->queue); -- Regards, Laurent Pinchart