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 68C4E1FF613; Thu, 27 Mar 2025 17:52:50 +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=1743097972; cv=none; b=FQzw2YnFbOw+j9D+T/SVGivgtTa+3qts9pav/z2hCK5tBN7mB4XR8YFxQBwOyxX3ci3gHHQE6WtVL54kJwm2pqwwTvGfG2oWJUYZXZkcG1YPla0iUVWHCxdHCs3Ij+D3D2sZsKjhjwyc/UE8eRdFJxTYapD4AyeLXSvMGbSKej0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743097972; c=relaxed/simple; bh=B4trpXe8O5u/J5Gdxudk+E4c7X8Ndwx0c+sAuF0EeW0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KqVy3olvLuFpom/yUBgjoKhxitJdRUWFiBUMZvBVa3Lh1x9qFcK1VPVpUh1AwHBQJSphrfZS63E6Gh7PzV5wiqS6NgdOPr+7d9/B1HrXSpMc2IEcuCvFT0pmNxNNfpOXzxUtrtRD5zzpGcCWqhTiBCTwaRaRp3qUGVH9ANmLODQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=rUivEjTP; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="rUivEjTP" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 00327446; Thu, 27 Mar 2025 18:50:59 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743097860; bh=B4trpXe8O5u/J5Gdxudk+E4c7X8Ndwx0c+sAuF0EeW0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rUivEjTP7nGtGkL4dTD6kiAIiXieGi012rId2g15CaG167WZxKKti6AmzYIUycvIy 0HXbHPptbJSU2Ro43LViHiP0uOQlwOOPFfBgZZ7cR7uGv2cocHqXC0klE+rXfFh4do sDCLlYt8AUSeW58LDAWULCoNqG+00Cc8w82mJOC0= Date: Thu, 27 Mar 2025 19:52:25 +0200 From: Laurent Pinchart To: Ricardo Ribalda Cc: Hans de Goede , Mauro Carvalho Chehab , Guennadi Liakhovetski , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Mauro Carvalho Chehab Subject: Re: [PATCH v5 3/5] media: uvcvideo: Increase/decrease the PM counter per IOCTL Message-ID: <20250327175225.GA11416@pendragon.ideasonboard.com> References: <20250303-uvc-granpower-ng-v5-0-a3dfbe29fe91@chromium.org> <20250303-uvc-granpower-ng-v5-3-a3dfbe29fe91@chromium.org> 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: <20250303-uvc-granpower-ng-v5-3-a3dfbe29fe91@chromium.org> Hi Ricardo, Thank you for the patch. On Mon, Mar 03, 2025 at 07:13:40PM +0000, Ricardo Ribalda wrote: > Now we call uvc_pm_get/put from the device open/close. This low > level of granularity might leave the camera powered on in situations > where it is not needed. > > Increase the granularity by increasing and decreasing the Power You're decreasing the granularity, not increasing it. > Management counter per ioctl. There are two special cases where the > power management outlives the ioctl: async controls and streamon. Handle > those cases as well. > > In a future patch, we will remove the uvc_pm_get/put from open/close. > > Reviewed-by: Hans de Goede > Signed-off-by: Ricardo Ribalda > --- > drivers/media/usb/uvc/uvc_ctrl.c | 13 +++++++++++-- > drivers/media/usb/uvc/uvc_v4l2.c | 23 +++++++++++++++++++++-- > drivers/media/usb/uvc/uvcvideo.h | 1 + > 3 files changed, 33 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 4e58476d305e..47188c7f96c7 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1594,12 +1594,15 @@ static void uvc_ctrl_set_handle(struct uvc_fh *handle, struct uvc_control *ctrl, > > if (ctrl->handle) { > WARN_ON(!ctrl->handle->pending_async_ctrls); > - if (ctrl->handle->pending_async_ctrls) > + if (ctrl->handle->pending_async_ctrls) { > ctrl->handle->pending_async_ctrls--; > + uvc_pm_put(handle->chain->dev); Shouldn't this be uvc_pm_put(ctrl->handle->chain->dev); ? In practice it won't make a difference as dev will be the same for both, but it seems clearer. > + } > } > > ctrl->handle = new_handle; > handle->pending_async_ctrls++; > + uvc_pm_get(handle->chain->dev); Similarly, we should use ctrl->handle here too (including for the pending_async_ctrls++). > return; > } > > @@ -1611,6 +1614,7 @@ static void uvc_ctrl_set_handle(struct uvc_fh *handle, struct uvc_control *ctrl, > if (WARN_ON(!handle->pending_async_ctrls)) > return; > handle->pending_async_ctrls--; > + uvc_pm_put(handle->chain->dev); > } > > void uvc_ctrl_status_event(struct uvc_video_chain *chain, > @@ -2815,6 +2819,7 @@ int uvc_ctrl_init_device(struct uvc_device *dev) > void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) > { > struct uvc_entity *entity; > + int i; > > guard(mutex)(&handle->chain->ctrl_mutex); > > @@ -2829,7 +2834,11 @@ void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) > } > } > > - WARN_ON(handle->pending_async_ctrls); > + if (!WARN_ON(handle->pending_async_ctrls)) > + return; > + > + for (i = 0; i < handle->pending_async_ctrls; i++) > + uvc_pm_put(handle->stream->dev); > } > > /* > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c > index de1e105f7263..1c9ac72be58a 100644 > --- a/drivers/media/usb/uvc/uvc_v4l2.c > +++ b/drivers/media/usb/uvc/uvc_v4l2.c > @@ -691,6 +691,9 @@ static int uvc_v4l2_release(struct file *file) > 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); > @@ -857,6 +860,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh, > return ret; > > handle->is_streaming = true; > + uvc_pm_get(stream->dev); > > return 0; > } > @@ -873,7 +877,10 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh, > guard(mutex)(&stream->mutex); > > uvc_queue_streamoff(&stream->queue, type); > - handle->is_streaming = false; > + if (handle->is_streaming) { > + handle->is_streaming = false; > + uvc_pm_put(stream->dev); > + } > > return 0; > } > @@ -1410,6 +1417,8 @@ static long uvc_v4l2_compat_ioctl32(struct file *file, > void __user *up = compat_ptr(arg); > long ret; > > + guard(uvc_pm)(handle->stream->dev); > + > switch (cmd) { > case UVCIOC_CTRL_MAP32: > ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up); > @@ -1444,6 +1453,16 @@ static long uvc_v4l2_compat_ioctl32(struct file *file, > } > #endif > > +static long uvc_v4l2_video_ioctl2(struct file *file, > + unsigned int cmd, unsigned long arg) > +{ > + struct uvc_fh *handle = file->private_data; > + > + guard(uvc_pm)(handle->stream->dev); > + > + return video_ioctl2(file, cmd, arg); > +} > + > static ssize_t uvc_v4l2_read(struct file *file, char __user *data, > size_t count, loff_t *ppos) > { > @@ -1529,7 +1548,7 @@ const struct v4l2_file_operations uvc_fops = { > .owner = THIS_MODULE, > .open = uvc_v4l2_open, > .release = uvc_v4l2_release, > - .unlocked_ioctl = video_ioctl2, > + .unlocked_ioctl = uvc_v4l2_video_ioctl2, I'd have named this uvc_v4l2_unlocked_ioctl. > #ifdef CONFIG_COMPAT > .compat_ioctl32 = uvc_v4l2_compat_ioctl32, > #endif > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index fbe3649c7cd6..eb8e374fa4c5 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -766,6 +766,7 @@ void uvc_status_put(struct uvc_device *dev); > /* PM */ > int uvc_pm_get(struct uvc_device *dev); > void uvc_pm_put(struct uvc_device *dev); > +DEFINE_GUARD(uvc_pm, struct uvc_device *, uvc_pm_get(_T), uvc_pm_put(_T)) > > /* Controls */ > extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops; -- Regards, Laurent Pinchart