From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 043A3C433DF for ; Tue, 16 Jun 2020 01:27:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB47E20739 for ; Tue, 16 Jun 2020 01:27:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="FQSvnTVB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726872AbgFPB1R (ORCPT ); Mon, 15 Jun 2020 21:27:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726564AbgFPB1Q (ORCPT ); Mon, 15 Jun 2020 21:27:16 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3FA5C061A0E; Mon, 15 Jun 2020 18:27:15 -0700 (PDT) Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 49F82F9; Tue, 16 Jun 2020 03:27:14 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1592270834; bh=yVhdm4SmO3wkXqvKwAY69etuikCBZKRYuD4KmrUh1q0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FQSvnTVBX3f5SqO3sC1FJmr87CZEgDB2GeYpJ6t1MWr7iPx3WCHsMIeMWAHX5JZcI pOrrNnySCtO4QjgIPkebFxXT7BA54jdQ6PDbGpZsuuJ9yLFv1kNM3GFqVsnb47mXX7 O3+D9HQC4H79Ays/zPN9+DcJXivDaescPY1p2scA= Date: Tue, 16 Jun 2020 04:26:52 +0300 From: Laurent Pinchart To: Dmitry Osipenko Cc: Thierry Reding , Sam Ravnborg , Rob Herring , Frank Rowand , dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 2/6] drm/of: Make drm_of_find_panel_or_bridge() to check graph's presence Message-ID: <20200616012652.GG1629@pendragon.ideasonboard.com> References: <20200614172234.8856-1-digetx@gmail.com> <20200614172234.8856-3-digetx@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200614172234.8856-3-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dmitry, Thank you for the patch. On Sun, Jun 14, 2020 at 08:22:30PM +0300, Dmitry Osipenko wrote: > When graph isn't defined in a device-tree, the of_graph_get_remote_node() > prints a noisy error message, telling that port node is not found. This is > undesirable behaviour in our case because absence of a panel/bridge graph > is a valid case. Let's check presence of the local port in a device-tree > before proceeding with parsing the graph. > > Reviewed-by: Sam Ravnborg > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/drm_of.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > index b50b44e76279..e0652c38f357 100644 > --- a/drivers/gpu/drm/drm_of.c > +++ b/drivers/gpu/drm/drm_of.c > @@ -239,13 +239,24 @@ int drm_of_find_panel_or_bridge(const struct device_node *np, > struct drm_bridge **bridge) > { > int ret = -EPROBE_DEFER; > - struct device_node *remote; > + struct device_node *local, *remote; > > if (!panel && !bridge) > return -EINVAL; > if (panel) > *panel = NULL; > > + /* > + * of_graph_get_remote_node() produces a noisy error message if port > + * node isn't found and the absence of the port is a legit case here, > + * so at first we silently check presence of the local port. > + */ > + local = of_graph_get_local_port(np); > + if (!local) > + return -ENODEV; > + > + of_node_put(local); > + The code looks fine, but you may want to take into account my proposal in 1/7 to instead create a of_graph_has_port() function. The could would be simpler here. > remote = of_graph_get_remote_node(np, port, endpoint); > if (!remote) > return -ENODEV; -- Regards, Laurent Pinchart