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 153CC4503B; Thu, 10 Apr 2025 17:50:38 +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=1744307441; cv=none; b=l4zt7GjKA+FcG3sUQlcvmoBFupTf4Je4NKpZDz4esCFUKcnOdV01ebwOUX7aL9IZ2M3GHxM/ag8E2p0+EOsLF4FuOibwF3Bh0mcoTCz2Hj+k1cm+cHGQUV2mmimxceGFYd6z5kuYQeSnRZaKdHxmk1a+eCcOBq0BeSuJyHcFNVc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744307441; c=relaxed/simple; bh=LU5dwri1TjU740CvlReL/wlTOs+9Az6hmBvzPrhh88E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FkQwjvG3X8GNXuDrVf4cyNorCRVzXuh3zTX5NyzRvnD2kQe6af35MvDsKmjx9Q69mZYUuVD8j44n94Xu3t9a2miY92lyd0+8GAxEnQknnWTp5uF9UJlT6vztCwjWoQIZnO/+XkZXK1xvBwvlkuDu7vrQMU2TyMRJyaAmoQZaIP8= 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=PDX8KAwg; 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="PDX8KAwg" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1ADA2352; Thu, 10 Apr 2025 19:48:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1744307318; bh=LU5dwri1TjU740CvlReL/wlTOs+9Az6hmBvzPrhh88E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PDX8KAwgi86ce2bRZRSSM1USB2zOndffk2GMIjRwwbDCSqGWV1F3a+IZni7iRoXln RYCqrRdwWQ2Y2IvcJWA/HS9azfvtog9PlEbC/ge0EEZyJUoa4DaurTI2AnfiVlXwoc sKXutYrzfCLnsHz2Rb4v83vflzuJZ4lomlBoCaFw= Date: Thu, 10 Apr 2025 20:50:10 +0300 From: Laurent Pinchart To: Nicolas Dufresne Cc: Sakari Ailus , Mauro Carvalho Chehab , Hans Verkuil , Tiffany Lin , Andrew-CT Chen , Yunfei Dong , Matthias Brugger , AngeloGioacchino Del Regno , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, kernel@collabora.com, linux-media@vger.kernel.org, Sebastian Fricke Subject: Re: [PATCH v2 1/5] media: mc: add manual request completion Message-ID: <20250410175010.GF27870@pendragon.ideasonboard.com> References: <20250410-sebastianfricke-vcodec_manual_request_completion_with_state_machine-v2-0-5b99ec0450e6@collabora.com> <20250410-sebastianfricke-vcodec_manual_request_completion_with_state_machine-v2-1-5b99ec0450e6@collabora.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: <20250410-sebastianfricke-vcodec_manual_request_completion_with_state_machine-v2-1-5b99ec0450e6@collabora.com> Hi Nicolas, Thank you for the patch. On Thu, Apr 10, 2025 at 11:39:56AM -0400, Nicolas Dufresne wrote: > From: Hans Verkuil > > By default when the last request object is completed, the whole > request completes as well. > > But sometimes you want to manually complete a request in a driver, > so add a manual complete mode for this. I didn't immediately understand this was about delaying completion of the request. It would be nice to make that more explicit in the commit message and in the documentation of media_request_mark_manual_completion(). A sample use case would also help. > In req_queue the driver marks the request for manual completion by > calling media_request_mark_manual_completion, and when the driver > wants to manually complete the request it calls > media_request_manual_complete(). > > Signed-off-by: Hans Verkuil > Signed-off-by: Nicolas Dufresne > --- > drivers/media/mc/mc-request.c | 38 ++++++++++++++++++++++++++++++++++++-- > include/media/media-request.h | 36 +++++++++++++++++++++++++++++++++++- > 2 files changed, 71 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/mc/mc-request.c b/drivers/media/mc/mc-request.c > index 5edfc2791ce7c7485def5db675bbf53ee223d837..398d0806d1d274eb8c454fc5c37b77476abe1e74 100644 > --- a/drivers/media/mc/mc-request.c > +++ b/drivers/media/mc/mc-request.c > @@ -54,6 +54,7 @@ static void media_request_clean(struct media_request *req) > req->access_count = 0; > WARN_ON(req->num_incomplete_objects); > req->num_incomplete_objects = 0; > + req->manual_completion = false; > wake_up_interruptible_all(&req->poll_wait); > } > > @@ -313,6 +314,7 @@ int media_request_alloc(struct media_device *mdev, int *alloc_fd) > req->mdev = mdev; > req->state = MEDIA_REQUEST_STATE_IDLE; > req->num_incomplete_objects = 0; > + req->manual_completion = false; > kref_init(&req->kref); > INIT_LIST_HEAD(&req->objects); > spin_lock_init(&req->lock); > @@ -459,7 +461,7 @@ void media_request_object_unbind(struct media_request_object *obj) > > req->num_incomplete_objects--; > if (req->state == MEDIA_REQUEST_STATE_QUEUED && > - !req->num_incomplete_objects) { > + !req->num_incomplete_objects && !req->manual_completion) { > req->state = MEDIA_REQUEST_STATE_COMPLETE; > completed = true; > wake_up_interruptible_all(&req->poll_wait); > @@ -488,7 +490,7 @@ void media_request_object_complete(struct media_request_object *obj) > WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED)) > goto unlock; > > - if (!--req->num_incomplete_objects) { > + if (!--req->num_incomplete_objects && !req->manual_completion) { > req->state = MEDIA_REQUEST_STATE_COMPLETE; > wake_up_interruptible_all(&req->poll_wait); > completed = true; > @@ -499,3 +501,35 @@ void media_request_object_complete(struct media_request_object *obj) > media_request_put(req); > } > EXPORT_SYMBOL_GPL(media_request_object_complete); > + > +void media_request_manual_complete(struct media_request *req) > +{ > + unsigned long flags; > + bool completed = false; > + > + if (WARN_ON(!req)) > + return; > + if (WARN_ON(!req->manual_completion)) > + return; > + > + spin_lock_irqsave(&req->lock, flags); > + if (WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED)) > + goto unlock; > + > + req->manual_completion = false; > + /* > + * It is expected that all other objects in this request are > + * completed when this function is called. WARN if that is > + * not the case. > + */ > + if (!WARN_ON(req->num_incomplete_objects)) { > + req->state = MEDIA_REQUEST_STATE_COMPLETE; > + wake_up_interruptible_all(&req->poll_wait); > + completed = true; > + } > +unlock: > + spin_unlock_irqrestore(&req->lock, flags); > + if (completed) > + media_request_put(req); > +} > +EXPORT_SYMBOL_GPL(media_request_manual_complete); > diff --git a/include/media/media-request.h b/include/media/media-request.h > index d4ac557678a78372222704400c8c96cf3150b9d9..645d18907be7148ca50dcc9248ff06bd8ccdf953 100644 > --- a/include/media/media-request.h > +++ b/include/media/media-request.h > @@ -56,6 +56,10 @@ struct media_request_object; > * @access_count: count the number of request accesses that are in progress > * @objects: List of @struct media_request_object request objects > * @num_incomplete_objects: The number of incomplete objects in the request > + * @manual_completion: if true, then the request won't be marked as completed > + * when @num_incomplete_objects reaches 0. Call media_request_manual_complete() > + * to set this field to false and complete the request I'd drop "set this field to false and " here. > + * if @num_incomplete_objects == 0. * after @num_incomplete_objects reaches 0. > * @poll_wait: Wait queue for poll > * @lock: Serializes access to this struct > */ > @@ -68,6 +72,7 @@ struct media_request { > unsigned int access_count; > struct list_head objects; > unsigned int num_incomplete_objects; > + bool manual_completion; > wait_queue_head_t poll_wait; > spinlock_t lock; > }; > @@ -218,6 +223,35 @@ media_request_get_by_fd(struct media_device *mdev, int request_fd); > int media_request_alloc(struct media_device *mdev, > int *alloc_fd); > > +/** > + * media_request_mark_manual_completion - Set manual_completion to true > + * > + * @req: The request > + * > + * Mark that the request has to be manually completed by calling > + * media_request_manual_complete(). > + * > + * This function should be called in the req_queue callback. s/should/shall/ unless it's not a hard requirement. Any way to catch incorrect call patterns ? > + */ > +static inline void > +media_request_mark_manual_completion(struct media_request *req) > +{ > + req->manual_completion = true; > +} > + > +/** > + * media_request_manual_complete - Set manual_completion to false The main purpose of the function is to complete the request, not setting manual_completion to false. > + * > + * @req: The request > + * > + * Set @manual_completion to false, and if @num_incomplete_objects > + * is 0, then mark the request as completed. > + * > + * If there are still incomplete objects in the request, then > + * WARN for that since that suggests a driver error. If that's an error then I'd document it more explicitly, as the first sentence makes it sound that both cases are valid. Maybe * This function completes a request that was marked for manual completion by an * earlier call to media_request_mark_manual_completion(). The request's * @manual_completion flag is reset to false. * * All objects contained in the request must have been completed previously. It * is an error to call this function otherwise. The request will not be * completed in that case, and the function will WARN. > + */ > +void media_request_manual_complete(struct media_request *req); > + > #else > > static inline void media_request_get(struct media_request *req) > @@ -336,7 +370,7 @@ void media_request_object_init(struct media_request_object *obj); > * @req: The media request > * @ops: The object ops for this object > * @priv: A driver-specific priv pointer associated with this object > - * @is_buffer: Set to true if the object a buffer object. > + * @is_buffer: Set to true if the object is a buffer object. > * @obj: The object > * > * Bind this object to the request and set the ops and priv values of -- Regards, Laurent Pinchart