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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5614CC3DA4A for ; Mon, 19 Aug 2024 07:21:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3028610E1B6; Mon, 19 Aug 2024 07:21:31 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bedKcfx0"; dkim-atps=neutral Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id B55D910E0E1; Sun, 18 Aug 2024 05:08:45 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 6D6CFCE03F7; Sun, 18 Aug 2024 05:08:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22EA0C32786; Sun, 18 Aug 2024 05:08:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723957722; bh=tLHjBLhxmFXEWqxbLa7VP5D2HxF8A4lSY0hSwJ/qc5M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bedKcfx0w9jhWw8P66djV4eyhZMxnyqdcrZTdTwp3los+uxy9iS2wKbIhVgZSnxN2 wYz7S4xWZIeBNhgqOpd1+omEFR6NEHTj81kA4Rd8JnFKWXNkwXbmeEjpNxCTSFGYSh 5M3yKvWHyUHVgBH+Ityom1j1WcaYJYdM+lVZrDlE= Date: Sun, 18 Aug 2024 07:08:39 +0200 From: Greg KH To: Kevin Holm Cc: stable@vger.kernel.org, regressions@lists.linux.dev, amd-gfx@lists.freedesktop.org, ML dri-devel , LKML , Wayne Lin , Jerry Zuo , Zaeem Mohamed , Daniel Wheeler , Alex Deucher Subject: Re: [PATCH 6.10] drm/amd/display: Refactor function dm_dp_mst_is_port_support_mode() Message-ID: <2024081800-owl-girdle-fd89@gregkh> References: <20240730185339.543359-1-kevin@holm.dev> <2024081739-suburb-manor-e6c3@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Mon, 19 Aug 2024 07:21:30 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Sat, Aug 17, 2024 at 10:30:41PM +0200, Kevin Holm wrote: > > > On 17.08.24 10:42, Greg KH wrote: > > On Tue, Jul 30, 2024 at 08:53:39PM +0200, Kevin Holm wrote: > > > From: Wayne Lin > > > > > > [ Upstream commit fa57924c76d995e87ca3533ec60d1d5e55769a27 ] > > > > > > [Why] > > > dm_dp_mst_is_port_support_mode() is a bit not following the original design rule and cause > > > light up issue with multiple 4k monitors after mst dsc hub. > > > > > > [How] > > > Refactor function dm_dp_mst_is_port_support_mode() a bit to solve the light up issue. > > > > > > Reviewed-by: Jerry Zuo > > > Acked-by: Zaeem Mohamed > > > Signed-off-by: Wayne Lin > > > Tested-by: Daniel Wheeler > > > Signed-off-by: Alex Deucher > > > [kevin@holm.dev: Resolved merge conflict in .../amdgpu_dm_mst_types.c] > > > Fixes: 4df96ba6676034 ("drm/amd/display: Add timing pixel encoding for mst mode validation") > > > Link: https://lore.kernel.org/stable/d74a7768e957e6ce88c27a5bece0c64dff132e24@holm.dev/T/#u > > > Signed-off-by: Kevin Holm > > > --- > > > I resolved the merge conflict so that, after this patch is applied to the > > > linux-6.10.y branch of the stable git repository, the resulting function > > > dm_dp_mst_is_port_support_mode (and also the new function > > > dp_get_link_current_set_bw) is identical to the original commit. > > > > > > I've confirmed that it fixes the regression I reported for my use case. > > > > And it turns out this change breaks the arm and arm64 builds. I tried > > to fix it up by applying the fixup afterward for this file, but it's > > just too much of a mess to unwind this, so I'm going to have to revert > > this now, sorry. > That sucks, sorry for the problems my patch caused. :( > > > See: > > https://lore.kernel.org/r/b27c5434-f1b1-4697-985b-91bb3e9a22df@roeck-us.net > > for details. > I unfortunately don't know the amdgpu driver and kernel code in general enough to help fix > that. The back-ported patch I send was my first patch to the kernel. > > In the email thread where I reported the problem I send a patch that reverts > 4df96ba6676034 ("drm/amd/display: Add timing pixel encoding for mst mode validation") to > fix the problem that way [1]. I've included a copy of that below. > I've tested that it still applies to 6.10.6-rc3 without conflicts and compiles for me. I > could not test if the 6.10.6-rc3 with the revert applied fixes the problem as I'm > traveling and don't have access to my normal setup. I can only say that reverting it on > v6.10.2 fixed the problem for me. > > I don't know how to compile for other architectures so I did not test that. > > Not sure what would be best, reverting the problem commit so the regression is fixed in > the 6.10 stable kernel (and maybe breaking something else?) or waiting for someone at AMD > with better knowledge of the amdgpu driver to back-port the fixing commit in a non-broken > way. Yes, this is up to the amd developers now, I suggest you work with them to get this resolved please. Or just use 6.11-rc3 and newer :) thanks, greg k-h