From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794049136; b=cPJDDCeeRuOv255uBlcDCbWCcudFHEk/S84fdQNtDV9RfsUpkXcXOn45wDZUnF+lYwN+ CQlPD1ADtFKDUGdMogUzs4MNQWk9iFUuFdzfbEBbKnhiHrnOYJgI3SA+2S+NRpyqOBR97 zJn+WIXaNID67Pk+Chx0EIIf6MgzvnkAgOGanuwVvqGGAktDfo901yuZqWmVf/Xg8CF+u MLSx3wKUJf2D4nWyKZD7XiQHz1cTLcJFCtMDkzi35caiW98e22noQg48MeEqUAt+qAuSB vTYIi9WxRPEYDnNZoPqthIyI2t6STM8zg3VSSE0K3pfZfnbbRBWjEOUCXR7z9z5xZ9w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049136; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=MHd/LCICnFSHvdTTTY7H/ksKF+IwtIviRt1cSmFVeYw=; b=qVyMUwflUF3gSeuoztKNLALRMy1Y66j1lsBwJQoCZoRKHdimgKr5e9+opyoqV/WGOzaT ca+yl5aigXn1N1N0DOFB5mcAS82FrvXhpbBpWiijvaLLieIZV3HYUXUuuYsrfFzohEujF 9Khlr6Vl/6VBWY7a7oXczBOOK2uOSuJ/0jfY87x5rfYAX+E4WYheGIU1d/4Zyl+/AcqW8 oLiPCEfZS0t9d/iNhCQVvec7XIzFQ0G0o27RasqBUIbjTxIYBVo/AhBFGkYB/ZdNY/Uko nBQDrxI2ZkysPiZXDQfTfgLRpmR4Z9FNxqLtAVKAZRZhYyFds8J4UgCQ7tHRLgSkhVA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=S2aAqf+H; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7E0D606A326 for ; Sat, 7 Nov 2026 10:58:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=S2aAqf+H Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5678C1F0089F; Sat, 7 Nov 2026 10:58:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049135; bh=MHd/LCICnFSHvdTTTY7H/ksKF+IwtIviRt1cSmFVeYw=; h=From:To:Cc:Subject:Date; b=S2aAqf+HUMUw4Hp0JwgLk/vMaehyOT678XaChj1J+yqZjlwElU8RrqPCEEF20rRex zIIqXgIHTqPXpcxPoJfzW6MUvABsQLVixccGxaV/Md3EQM8+LExo8A/uSszMEWWb+A 17mhTv4DUu6ZpTbdUyuuz3jCeJ6E86tc/5EHaEAGjaaadjIyN53SDCij7DQKPNIMgR TBkeN5AmGg7OuOe+wGTzkBXwLvR0dASvZo0a6/g3QzotEOwf4S3NE0PS7Nysr7adYI xsOAW7LqbHNoocP9AxTnVpn0xaHB8fhwMY4/PEvuv709xvjsz99wsMtT+x37yYrUG2 zrlUqWt/vwPRQ== From: Sasha Levin To: imre.deak@intel.com, luciano.coelho@intel.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] drm/i915/dp_mst: Fix configuring FEC for a disconnected stream" failed to apply to 5.15-stable tree Date: Sat, 7 Nov 2026 05:58:54 -0500 Message-ID: <20261107055853-failed-5.15-270681fbffbb@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 270681fbffbba2b6ccf5b7e3c34b8b563b36167f # git commit -s git send-email --to '' --in-reply-to '20261107055853-failed-5.15-270681fbffbb@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 270681fbffbba2b6ccf5b7e3c34b8b563b36167f Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Mon, 7 Sep 2026 20:44:12 +0300 Subject: [PATCH] drm/i915/dp_mst: Fix configuring FEC for a disconnected stream During an atomic commit after all the MST stream CRTC state is computed the driver ensures that the FEC is configured the same way (enabled or disabled) for all the streams on a given MST topology's link. drm_dp_mst_port_downstream_of_parent() used to determine if a stream is downstream of an MST port will return false if the whole topology is disconnected, since in that case it can't verify that the port/ parent_port passed to it is in the given MST topology. This is a problem during the above FEC configuration check, since intel_dp_mst_check_dsc_change()->get_pipes_downstream_of_mst_ports() will not return all the stream CRTCs/pipes for the topology as expected. Since passing parent_port==NULL to get_pipes_downstream_of_mst_port() is meant to return all the streams for the given topology (i.e. mst_mgr) skip checking if an MST port is downstream of a parent port in this case. This fixes a problem where the FEC configuration check explained above failed to ensure that all streams' FEC is configured the same way if the topology was disconnected, leading to a FEC state mismatch error. Cc: stable@vger.kernel.org # v6.10+ Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16073 Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16384 Reviewed-by: Luca Coelho Signed-off-by: Imre Deak Link: https://patch.msgid.link/20260907174413.741851-1-imre.deak@intel.com --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 6a869d0f6ffc0..20766b6c0bcfa 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -856,7 +856,8 @@ static u8 get_pipes_downstream_of_mst_port(struct intel_atomic_state *state, if (&connector->mst.dp->mst.mgr != mst_mgr) continue; - if (connector->mst.port != parent_port && + if (parent_port && + connector->mst.port != parent_port && !drm_dp_mst_port_downstream_of_parent(mst_mgr, connector->mst.port, parent_port)) -- 2.53.0