From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 26062946F; Sun, 18 Aug 2024 05:08:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723957723; cv=none; b=r4S5+axTQ8lgtL/JB3iteSYz2CLw2urvjvKAluFEPMYTknE0rQjY0UE0mUYk5EQYV0itwXHBp5wT8RG8HtwF+s6JZyVGijxyO8OYtbeZ2cAOymZkJaOfvnYjEjcTbdf7U0kqEfUxwxQG3/mx0c5s9flnhB0lYAbcM4r/W4qx4n8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723957723; c=relaxed/simple; bh=tLHjBLhxmFXEWqxbLa7VP5D2HxF8A4lSY0hSwJ/qc5M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VWui8rE/2NIuT2w0hWHEorZ3PBPkaUG+ZstsEi//yRnNB8IFPBcfYxI3/63VhkemNk3TcWCe4MY/0a2M2UzNe9MT0RGFs5t6SVXMhiZJK5qSnMUAy41nau1L1EFKkCHy+3N1w0/cyhoH1ntYys351L+NbLRQ3PWMn4dU8aXID3U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bedKcfx0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bedKcfx0" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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