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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 858C1C433EF for ; Tue, 28 Sep 2021 12:49:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66CA2610E5 for ; Tue, 28 Sep 2021 12:49:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240815AbhI1Muy (ORCPT ); Tue, 28 Sep 2021 08:50:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240685AbhI1Mux (ORCPT ); Tue, 28 Sep 2021 08:50:53 -0400 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDE86C061575 for ; Tue, 28 Sep 2021 05:49:13 -0700 (PDT) Received: from [IPv6:::1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 15F728312F; Tue, 28 Sep 2021 14:49:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1632833348; bh=HjmkWr+4r7r/atswVfbKvnliuyMeP34ao4ebbIjZUtM=; h=Subject:To:References:Cc:From:Date:In-Reply-To:From; b=IOUnQ3AXIukz2Q6cbalRMcafkhbVnnKHazpvZGHH8S8s3UisQ5pNlZLcMSlIkgQis LpLOZqzqcfLGef6vV0ovLFia7jJVRey1BTtYpQhuUReCDKZQ2srX2/962ii8r86Rvs dxEBhTY7Vx9GE1UVaCNkubjzXF00BJggQU0e31pgUHZ9RY18UMKlWT+Q3rLIiDkgox yz2RGAPIXUfQ8zBBAXjK3lDwIrMgQt4Avg3RpejNmAYMbwSB47TLHJQsGC97JmG7R4 sVPCt03h45R7EQZQusYaZPZby88qY6JlHbeGto+1aW9Z87Mw9wRRCyEVne4iidRRUy uXxwGxkc+TDXg== Subject: Re: [PATCH v1 2/5] drm: mxsfb: Set proper default bus format when using a bridge To: =?UTF-8?Q?Guido_G=c3=bcnther?= References: <1fd5457b925249bce77315663adabecdd29ec0f3.1632828477.git.agx@sigxcpu.org> Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , Stefan Agner , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Thierry Reding , Sam Ravnborg , Ondrej Jirman , Lucas Stach , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Marek Vasut Message-ID: <67e6056a-6157-795d-908d-d65cc803c03d@denx.de> Date: Tue, 28 Sep 2021 14:49:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <1fd5457b925249bce77315663adabecdd29ec0f3.1632828477.git.agx@sigxcpu.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/28/21 2:16 PM, Guido Günther wrote: > If a bridge doesn't do any bus format handling MEDIA_BUS_FMT_FIXED is > returned. Fallback to a reasonable default (MEDIA_BUS_FMT_RGB888_1X24) in > that case. > > This unbreaks e.g. using mxsfb with the nwl bridge and mipi panels. > > Fixes: b776b0f00f24 ("drm: mxsfb: Use bus_format from the nearest bridge if present") > > Reported-by: Martin Kepplinger > Signed-off-by: Guido Günther > --- > drivers/gpu/drm/mxsfb/mxsfb_kms.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c > index d6abd2077114..f4be16f5c20b 100644 > --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c > +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c > @@ -369,6 +369,11 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc, > drm_atomic_get_new_bridge_state(state, > mxsfb->bridge); > bus_format = bridge_state->input_bus_cfg.format; > + if (bus_format == MEDIA_BUS_FMT_FIXED) { > + dev_warn_once(drm->dev, > + "Bridge does not provide bus format. Please fix."); Fix what ? Oh ... the bridge driver ? Maybe such a hint should be in the warning message. And it might be useful to explain how to fix that bridge driver, or at least provide some reference to an example (like this nwl patch series). > + bus_format = MEDIA_BUS_FMT_RGB888_1X24; The warning should also mention that the driver is falling back to this mode.