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 921EDC00A8F for ; Tue, 24 Oct 2023 07:48:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232592AbjJXHss (ORCPT ); Tue, 24 Oct 2023 03:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232544AbjJXHss (ORCPT ); Tue, 24 Oct 2023 03:48:48 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0981B7 for ; Tue, 24 Oct 2023 00:48:45 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E548C433C8; Tue, 24 Oct 2023 07:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698133724; bh=WnmC6H7ZmmJ51nYNdcmp3NTy1FXn+2ppOtiZX2acN/I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zMOcYjHEzCvJckkZnC64iyUNu7KQqgvKspnrEoD1BBAFfOyBo4PqAjJEIySBMt+QM sQAXFTfaHYtND7scx810M2OP8hLN0wNnpoCoVlmg7Pa5Ts28rrfh8dczusJ/3bbxQ9 QDFrqQBkNU7SlZ0V1eTF6Sk+DyQ20QC8rYuKyC38= Date: Tue, 24 Oct 2023 09:48:42 +0200 From: Greg Kroah-Hartman To: Doug Anderson Cc: stable@vger.kernel.org, patches@lists.linux.dev, Anton Bambura , Hsin-Yi Wang , Sasha Levin Subject: Re: [PATCH 6.5 219/241] drm/panel: Move AUX B116XW03 out of panel-edp back to panel-simple Message-ID: <2023102433-sabbath-clarinet-2b6f@gregkh> References: <20231023104833.832874523@linuxfoundation.org> <20231023104839.191685463@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Oct 23, 2023 at 07:35:36AM -0700, Doug Anderson wrote: > Hi, > > On Mon, Oct 23, 2023 at 4:12 AM Greg Kroah-Hartman > wrote: > > > > 6.5-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Douglas Anderson > > > > [ Upstream commit ad3e33fe071dffea07279f96dab4f3773c430fe2 ] > > > > In commit 5f04e7ce392d ("drm/panel-edp: Split eDP panels out of > > panel-simple") I moved a pile of panels out of panel-simple driver > > into the newly created panel-edp driver. One of those panels, however, > > shouldn't have been moved. > > > > As is clear from commit e35e305eff0f ("drm/panel: simple: Add AUO > > B116XW03 panel support"), AUX B116XW03 is an LVDS panel. It's used in > > exynos5250-snow and exynos5420-peach-pit where it's clear that the > > panel is hooked up with LVDS. Furthermore, searching for datasheets I > > found one that makes it clear that this panel is LVDS. > > > > As far as I can tell, I got confused because in commit 88d3457ceb82 > > ("drm/panel: auo,b116xw03: fix flash backlight when power on") Jitao > > Shi added "DRM_MODE_CONNECTOR_eDP". That seems wrong. Looking at the > > downstream ChromeOS trees, it seems like some Mediatek boards are > > using a panel that they call "auo,b116xw03" that's an eDP panel. The > > best I can guess is that they actually have a different panel that has > > similar timing. If so then the proper panel should be used or they > > should switch to the generic "edp-panel" compatible. > > > > When moving this back to panel-edp, I wasn't sure what to use for > > .bus_flags and .bus_format and whether to add the extra "enable" delay > > from commit 88d3457ceb82 ("drm/panel: auo,b116xw03: fix flash > > backlight when power on"). I've added formats/flags/delays based on my > > (inexpert) analysis of the datasheet. These are untested. > > > > NOTE: if/when this is backported to stable, we might run into some > > trouble. Specifically, before 474c162878ba ("arm64: dts: mt8183: > > jacuzzi: Move panel under aux-bus") this panel was used by > > "mt8183-kukui-jacuzzi", which assumed it was an eDP panel. I don't > > know what to suggest for that other than someone making up a bogus > > panel for jacuzzi that's just for the stable channel. > > > > Fixes: 88d3457ceb82 ("drm/panel: auo,b116xw03: fix flash backlight when power on") > > Fixes: 5f04e7ce392d ("drm/panel-edp: Split eDP panels out of panel-simple") > > Tested-by: Anton Bambura > > Acked-by: Hsin-Yi Wang > > Signed-off-by: Douglas Anderson > > Link: https://patchwork.freedesktop.org/patch/msgid/20230925150010.1.Iff672233861bcc4cf25a7ad0a81308adc3bda8a4@changeid > > Signed-off-by: Sasha Levin > > --- > > drivers/gpu/drm/panel/panel-edp.c | 29 ----------------------- > > drivers/gpu/drm/panel/panel-simple.c | 35 ++++++++++++++++++++++++++++ > > 2 files changed, 35 insertions(+), 29 deletions(-) > > I responded to Sasha but managed to miss CCing stable@. My > apologies... Copying what I wrote there: > > --- > > I feel that this should not be added to any stable trees. Please > remove it from the 6.1 and 6.5 stable trees and, if possible, mark it > so it won't get auto-selected in the future. > > The issue here is that several mediatek boards ended up (incorrectly) > claiming that they included this panel and this change has the > possibility to break those boards. In the latest upstream kernel > mediatek boards that were using it have switched to the generic > "edp-panel" compatible string, but if this is backported someplace > before that change it has the potential to break folks. > > It should be noted that it was confirmed that the "snow" and > "peach-pit" boards appeared to be working even without this patch, so > there is no burning need (even for those boards) to get this patch > backported. > > For discussion on the topic, please see the link pointed to by the patch, AKA: > > https://patchwork.freedesktop.org/patch/msgid/20230925150010.1.Iff672233861bcc4cf25a7ad0a81308adc3bda8a4@changeid > > --- > > Sasha has already said he'd remove it from the queue, but responding > here just in case it's important. Thanks! He's dropped them now, thanks! greg k-h