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 B939C1D86E4; Tue, 30 Jun 2026 10:24:32 +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=1782815074; cv=none; b=P0ifFpeRubkP0v0R9uvWy6S1SdICQsVceEhk1eNv8gVwN58zNqzaDKDP7azZzA23TCg24EmPRZOZZXbPOzgAD5hwbBnQ6WXDIKkMJ4MizGnI9kb4+6aURy2v8R3rIM4nXiEX52s2R/N8bKNvDjmFGACfkJkM5slq2Y7eHP1kf9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782815074; c=relaxed/simple; bh=erQe7Ne8OmWbJg7ppUflzaGfxgmL/j+6V765gCDZzb8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qJGZx6/jwVk3Gy8b+79+qTkeKhkYzXK8hqvk3kW38rxlrC9b6UFKSinBXirn9gvQvbNaQ/sr3rOH5Z7ojplRTUBNp/nMw8CM5o2cOLxArSuGiLmS3tUsdGrqcLJ8/Il1YaupnT3L6OCpparxkDqlRBQSBRYctCmblnajumFjZBo= 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=dqN/PDvr; 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="dqN/PDvr" Received: from killaraus.ideasonboard.com (2001-14ba-70f3-e800--a06.rev.dnainternet.fi [IPv6:2001:14ba:70f3:e800::a06]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 007B7D52; Tue, 30 Jun 2026 12:23:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1782815027; bh=erQe7Ne8OmWbJg7ppUflzaGfxgmL/j+6V765gCDZzb8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dqN/PDvrl/AFFGllCuBKDq9yNUS735xMxbgNHCi8n+eryt5VJGF2ki70hx92GA6nG +fVfb9PfBVo7AuNGec/HbtDl+EjBIC9HvSEZf2sun984ra2171XfRJTn/uxBfbd8X5 PFR0x+DiMp64j/u1Yiwk5MIY0ivMfEXl0L0r0gmg= Date: Tue, 30 Jun 2026 13:24:29 +0300 From: Laurent Pinchart To: Shih-Sheng Yang Cc: hverkuil+cisco@kernel.org, kees@kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, Sakari Ailus Subject: Re: [PATCH] media: v4l2-dev: fix media controller registration error handling Message-ID: <20260630102429.GA3199975@killaraus.ideasonboard.com> References: <20260626192257.GA2894880@killaraus.ideasonboard.com> <20260630095456.1745545-1-yshihsheng@gmail.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: <20260630095456.1745545-1-yshihsheng@gmail.com> On Tue, Jun 30, 2026 at 05:54:56PM +0800, Shih-Sheng Yang wrote: > Hi Laurent, > > Thank you for the review. > > I've addressed this in v2 by moving the NULL check into > media_devnode_remove() and by using device_unregister() in > __video_register_device(), as device_register() has already succeeded > there. > > I also checked the other media_devnode_remove() callers. I didn't find > another caller with the same failure pattern or an immediate risk that > requires changing the helper API. Since changing media_devnode_remove() > to take a pointer-to-pointer would affect a wider set of callers, I have > left that out of v2. I can add it if you prefer. Sakari, Hans, to you have an opinion on that pattern ? If you forget the context, the idea is to turn void media_devnode_remove(struct media_intf_devnode *devnode) { media_remove_intf_links(&devnode->intf); media_gobj_destroy(&devnode->intf.graph_obj); kfree(devnode); } into void media_devnode_remove(struct media_intf_devnode **devnode) { struct media_intf_devnode *node = *devnode; if (!node) return; media_remove_intf_links(&node->intf); media_gobj_destroy(&node->intf.graph_obj); kfree(node); *devnode = NULL; } (bikeshedding on whether or not we need a local variable is left for later) I think the pattern is safer, but it's not common in V4L2 at the moment. -- Regards, Laurent Pinchart