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 11C9113DDB5; Thu, 28 Nov 2024 21:26:40 +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=1732829202; cv=none; b=Pv1Rdr0JsVYEHVT5CvW5InEvNPOvNFEArqLRA3KkknlolBeKijnDAREg/30sNFiJgQpZDt6wS4IuO6L2W70LrynEBdIBHYrOxA0KuJHGUmui4RMhRHqos/U/QY1HiMdc/Olq2/TwqZ0jaRvFmclisCMkm/dvzWB96SPWwLrkvWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732829202; c=relaxed/simple; bh=jTD98gw1TXfjIIaWmmT4g6efz3BLtsEwLiRUIRQJkJ0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YF4JNGxEUyBiKJ5Xxu0giDrPv6lLi/VjANZvggwWJ9bl4MmzmIaQtg2dvHHbvNf7a7R2H4u5R7msKEUouJTdxtogZgg98q4yDpRyJLZpvgKJV/mXTG6Vig20bXiTiFnrG3W0nDRN85UhdzhjWbvzm/HEmlr4uTLYMHYaFAT3QSQ= 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=Fyl3n1OA; 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="Fyl3n1OA" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 03F7C526; Thu, 28 Nov 2024 22:26:14 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1732829175; bh=jTD98gw1TXfjIIaWmmT4g6efz3BLtsEwLiRUIRQJkJ0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Fyl3n1OATRT+XAw6kBlAD59w61JIF+LaPWFoZp5UW5QGk4kJUdL3GvzIgtSwF+/zf n9GcKRTD8S7Zp8XNky6NBMhoRay1KpWNEgsvDPBr1M+u87ZpA174qfwanxJxZJxWQo QVj4yqsu3xcm9rxVjhUSe3T42IiJ7PVlwzXSL9FQ= Date: Thu, 28 Nov 2024 23:26:28 +0200 From: Laurent Pinchart To: Ricardo Ribalda Cc: Hans de Goede , Mauro Carvalho Chehab , Guennadi Liakhovetski , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 4/4] media: uvcvideo: Remove redundant NULL assignment Message-ID: <20241128212628.GD25731@pendragon.ideasonboard.com> References: <20241127-uvc-fix-async-v2-0-510aab9570dd@chromium.org> <20241127-uvc-fix-async-v2-4-510aab9570dd@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@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: <20241127-uvc-fix-async-v2-4-510aab9570dd@chromium.org> Hi Ricardo, Thank you for the patch. On Wed, Nov 27, 2024 at 12:14:52PM +0000, Ricardo Ribalda wrote: > ctrl->handle will only be different than NULL for controls that have > mappings. This is because that assignment is only done inside > uvc_ctrl_set() for mapped controls. That seems right. I checked the unplug paths, and the mappings are destroyed from uvc_delete(), after all file handles get closed. I think this patch should go first in the series, as otherwise there's a temporary state where you rely on handle never being touched without holding the proper lock, and this code path violates that requirement. Is there anything I may be missing that would cause issues with bisection if I move this patch at the beginning of the series ? > Signed-off-by: Ricardo Ribalda Reviewed-by: Laurent Pinchart > --- > drivers/media/usb/uvc/uvc_ctrl.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 99ddc5e9dff8..b9c9ff629ab6 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1645,10 +1645,8 @@ bool uvc_ctrl_status_event_async(struct urb *urb, struct uvc_video_chain *chain, > struct uvc_device *dev = chain->dev; > struct uvc_ctrl_work *w = &dev->async_ctrl; > > - if (list_empty(&ctrl->info.mappings)) { > - ctrl->handle = NULL; > + if (list_empty(&ctrl->info.mappings)) > return false; > - } > > w->data = data; > w->urb = urb; -- Regards, Laurent Pinchart