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=1794047359; b=gY4iVnv6naWC70ElqT3hC9LLHApeXHFLIai9wyB/Ruw6SVyLQViSYxmGdIO06lkxZCkV NbYqNCIK3kJe5E5kUBrw2JvWR2JeuJaG/CCf36a3nqPNbHsmoR8n3RMnWeglZsoa04du3 ZzdfmSbX2zQ4vSU5Xajmg2radjAv+3gnqS6/2qE3OHH/1V+VCtdM98jfSz/6JsQVgi/dH zsetXf10yWsdrcuotY5T5PblagL0thR7IRNXQ80rvjZz47+kx6FC9kVMGXu7Et0bFhmmI bZKgjLUBJLmckeMc9s9U7JlklT9Gsf9H09QCdg4JS/mvV/08cwujJOa6uhUxJaz4Fsw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047359; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=MHNo6hceOKzxY4N0S1zOBVJxCeUyNLQ2bxyA6EcpUSs=; b=w/9khEK4I0RTTJByJf3M0hmeyp2Q8hkuMJU17QyCKI1RByWqzu+2bD8Vzy3hpyACrRHx SdmIMdovJpHVmRZmMxQt4np1q67RMrJBMmnF1XKJuAsJ6lV7MvVjCH/5uhmD/s6+JpiFI vyHhtXP1WDwVECPAX5nduDB0/Ci9nVjXY1qp7bD5URBtWnBEHa07fupEBbDvK/xcu3Xph MZQqvejyGux4EqvIoYYUkyFpthIHLjZQsaA7ABNYDcnM9CbyMFYpbEDZEksxAEBP8gza1 WU0LoQjLSpCWbTXCxuaagv8GOFAp12Em4yRlI4WocetpK3+Y/MeMnh4Qkt/efFGheNw== 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=juiXxbl3; 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 53642606D80B for ; Sat, 7 Nov 2026 10:29:19 +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=juiXxbl3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id C454B1F0089F; Sat, 7 Nov 2026 10:29:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047359; bh=MHNo6hceOKzxY4N0S1zOBVJxCeUyNLQ2bxyA6EcpUSs=; h=From:To:Cc:Subject:Date; b=juiXxbl3uYmvaXCYrSDVlJuXZxUil8TdBXEfG4rJJMbdA1gwTiaPbHh3tCqZ8kA+j 1FTdKG8CoII7QLpUxsWYOTevi19Al0qARzviAGOSRhq9ymM/kXhO5vVs/vcZafXcgq A0/GENHxcAK5fAZ6UUJnLMTNP49wnwNO4cq2VRViGyLfw6e8NrMIuwYB9e2R0yDPmn 0HYckLOF/ops6nHbz8E3yJduWlxQ+TbykPbrADQuBNHtu5p1Xzj97rIo1nzdamuvXq Or68Df4cBMDGDPkCEMIIaK8a49mKBpPQ4BtiIgrBWYyUUUW3lw3TaLfEz+BGGy7m0n 7jOyGoZLvIYqA== 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 6.6-stable tree Date: Sat, 7 Nov 2026 05:29:17 -0500 Message-ID: <20261107052917-failed-6.6-270681fbffbb@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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 270681fbffbba2b6ccf5b7e3c34b8b563b36167f # git commit -s git send-email --to '' --in-reply-to '20261107052917-failed-6.6-270681fbffbb@kernel.org' --subject-prefix 'PATCH 6.6.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