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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E10F6C433EF for ; Sat, 12 Feb 2022 15:06:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236337AbiBLPG0 convert rfc822-to-8bit (ORCPT ); Sat, 12 Feb 2022 10:06:26 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:59760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229960AbiBLPGZ (ORCPT ); Sat, 12 Feb 2022 10:06:25 -0500 Received: from aposti.net (aposti.net [89.234.176.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DD5A214; Sat, 12 Feb 2022 07:06:21 -0800 (PST) Date: Sat, 12 Feb 2022 15:06:07 +0000 From: Paul Cercueil Subject: Re: [PATCH v14 5/9] drm/bridge: dw-hdmi: repair interworking with hdmi-connector for jz4780 To: "H. Nikolaus Schaller" Cc: Rob Herring , Mark Rutland , Thomas Bogendoerfer , Geert Uytterhoeven , Kees Cook , "Eric W. Biederman" , Miquel Raynal , David Airlie , Daniel Vetter , Neil Armstrong , Robert Foss , Laurent Pinchart , Jernej Skrabec , Harry Wentland , Sam Ravnborg , Maxime Ripard , Hans Verkuil , Liam Girdwood , Mark Brown , Paul Boddie , Andrzej Hajda , Kieran Bingham , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org, Jonas Karlman , dri-devel@lists.freedesktop.org Message-Id: <7Y577R.WAL64FW8KJZJ1@crapouillou.net> In-Reply-To: <8703a3e48574c09e8756b79e8f69be7d84926fe9.1644675566.git.hns@goldelico.com> References: <8703a3e48574c09e8756b79e8f69be7d84926fe9.1644675566.git.hns@goldelico.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nikolaus, Le sam., févr. 12 2022 at 15:19:23 +0100, H. Nikolaus Schaller a écrit : > Commit 7cd70656d1285b ("drm/bridge: display-connector: implement bus > fmts callbacks") > > introduced a new mechanism to negotiate bus formats between hdmi > connector > and the synopsys hdmi driver inside the jz4780. > > By this, the dw-hdmi is no longer the only bridge and sets up a list > of formats in dw_hdmi_bridge_atomic_get_output_bus_fmts(). > > This includes MEDIA_BUS_FMT_UYVY8_1X16 which is chosen for the jz4780 > but only > produces a black screen. Neil pushed a fix yesterday that looks like it could fix your issue. The fix is: 1528038385c0 ("drm/bridge: dw-hdmi: use safe format when first in bridge chain") Could you try if it does indeed fix your issue? Cheers, -Paul > This fix is based on the observation that max_bpc = 0 when running > this > function while info->bpc = 8. Since the formats checks before this > always test > for max_bpc >= info->pbc indirectly my assumption is that we must > check it > here as well. > > Adding the proposed patch makes the CI20/jz4780 panel work again in > MEDIA_BUS_FMT_RGB888_1X24 mode. > > Fixes: 7cd70656d1285b ("drm/bridge: display-connector: implement bus > fmts callbacks") > Signed-off-by: H. Nikolaus Schaller > --- > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index b0d8110dd412c..826a055a7a273 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -2620,10 +2620,10 @@ static u32 > *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, > output_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30; > } > > - if (info->color_formats & DRM_COLOR_FORMAT_YCBCR422) > + if (max_bpc >= info->bpc && info->color_formats & > DRM_COLOR_FORMAT_YCBCR422) > output_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16; > > - if (info->color_formats & DRM_COLOR_FORMAT_YCBCR444) > + if (max_bpc >= info->bpc && info->color_formats & > DRM_COLOR_FORMAT_YCBCR444) > output_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24; > > /* Default 8bit RGB fallback */ > -- > 2.33.0 >