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 EF15B27702; Thu, 11 Apr 2024 05:16:42 +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=1712812604; cv=none; b=TfX+0y1TOeC0hp2eAY4FA7O/q6n6d9g0Tlbp9dyQdhiqcZIUDxQqRVBA3s8uMxdO4YiEJXiIompDE8x6gR156nBsHSuD0uZmFGFYr3QXEljAhTfD8Z1I4QNF/bsx/TNp0/7b+E49EAP7/NVxSRtkHzYFyxKUZ+SLBkgEfEMAExU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712812604; c=relaxed/simple; bh=ijLlkfEOixlQrBb4bdG6kkTwGrC0yh3+ME1KUOt1vj0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=q1Yk069fJTJX0qjDiwuW5u/PyfP8n3TUX9SxLOgWjsH3TtejmtXnWvdJmXYAvhgK8WYF0F90FATui2Ox005x3fFnmYozcEUQX62J3b9cCRSupSavohL0QyGdmgDqjA5bq2uQ6fkfvfWwsUaxDGeVTsa/ak+Mkk0YJhOPF5jQj3A= 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=p4pegSC5; 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="p4pegSC5" Received: from [192.168.1.108] (unknown [103.86.18.224]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 6CB07E1; Thu, 11 Apr 2024 07:15:56 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1712812558; bh=ijLlkfEOixlQrBb4bdG6kkTwGrC0yh3+ME1KUOt1vj0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=p4pegSC56pJULx/a8E8LMIJUc3iQrlti8xQQnHrZTV2LeRzwVkxr8XulFT+Us5X5U iYpUHrV4vjS1gHyK/Sd9QQtpa548O8r4vi52QExCO+qL7YtCI3WBANJyYm65t+0NXG tWqY+/2Sai8aZXnnCF0uMisGu4n8jOFN9PO5AiVw= Message-ID: Date: Thu, 11 Apr 2024 10:46:33 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/9] media: subdev: Fix use of sd->enabled_streams in call_s_stream() Content-Language: en-US To: Tomi Valkeinen , Mauro Carvalho Chehab , Hans Verkuil , Laurent Pinchart , Sakari Ailus Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20240410-enable-streams-impro-v3-0-e5e7a5da7420@ideasonboard.com> <20240410-enable-streams-impro-v3-4-e5e7a5da7420@ideasonboard.com> From: Umang Jain In-Reply-To: <20240410-enable-streams-impro-v3-4-e5e7a5da7420@ideasonboard.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Tomi, Thank you for the patch On 10/04/24 6:05 pm, Tomi Valkeinen wrote: > call_s_stream() uses sd->enabled_streams to track whether streaming has > already been enabled. However, > v4l2_subdev_enable/disable_streams_fallback(), which was the original > user of this field, already uses it, and > v4l2_subdev_enable/disable_streams_fallback() will call call_s_stream(). > > This leads to a conflict as both functions set the field. Afaics, both > functions set the field to the same value, so it won't cause a runtime > bug, but it's still wrong and if we, e.g., change how > v4l2_subdev_enable/disable_streams_fallback() operates we might easily > cause bugs. > > Fix this by adding a new field, 'streaming_enabled', for > call_s_stream(). Just a suggestion, as this is only used in call_s_stream(), maybe naming this field 's_stream_enabled' ? Rest looks good to me, Reviewed-by: Umang Jain > > Signed-off-by: Tomi Valkeinen > --- > drivers/media/v4l2-core/v4l2-subdev.c | 8 ++------ > include/media/v4l2-subdev.h | 3 +++ > 2 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > index 606a909cd778..6cd353d83dfc 100644 > --- a/drivers/media/v4l2-core/v4l2-subdev.c > +++ b/drivers/media/v4l2-core/v4l2-subdev.c > @@ -421,12 +421,8 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable) > * The .s_stream() operation must never be called to start or stop an > * already started or stopped subdev. Catch offenders but don't return > * an error yet to avoid regressions. > - * > - * As .s_stream() is mutually exclusive with the .enable_streams() and > - * .disable_streams() operation, we can use the enabled_streams field > - * to store the subdev streaming state. > */ > - if (WARN_ON(!!sd->enabled_streams == !!enable)) > + if (WARN_ON(sd->streaming_enabled == !!enable)) > return 0; > > ret = sd->ops->video->s_stream(sd, enable); > @@ -437,7 +433,7 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable) > } > > if (!ret) { > - sd->enabled_streams = enable ? BIT(0) : 0; > + sd->streaming_enabled = enable; > > if (enable) > v4l2_subdev_enable_privacy_led(sd); > diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h > index a9e6b8146279..f55d03e0acc1 100644 > --- a/include/media/v4l2-subdev.h > +++ b/include/media/v4l2-subdev.h > @@ -1043,6 +1043,8 @@ struct v4l2_subdev_platform_data { > * v4l2_subdev_enable_streams() and > * v4l2_subdev_disable_streams() helper functions for fallback > * cases. > + * @streaming_enabled: Tracks whether streaming has been enabled with s_stream. > + * This is only for call_s_stream() internal use. > * > * Each instance of a subdev driver should create this struct, either > * stand-alone or embedded in a larger struct. > @@ -1091,6 +1093,7 @@ struct v4l2_subdev { > */ > struct v4l2_subdev_state *active_state; > u64 enabled_streams; > + bool streaming_enabled; > }; > > >