FAILED: patch "[PATCH] drm/i915/dp_mst: Fix configuring TUs for a disconnected" failed to apply to 6.12-stable tree
[email protected]
maintainerThe patch below does not apply to the 6.12-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 <[email protected]>.
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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x a443e0b8d647c1401b110d9f919d8c6cb8607260
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026092957-hardening-slingshot-e073@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a443e0b8d647c1401b110d9f919d8c6cb8607260 Mon Sep 17 00:00:00 2001
From: Imre Deak <[email protected]>
Date: Mon, 7 Sep 2026 20:44:13 +0300
Subject: [PATCH] drm/i915/dp_mst: Fix configuring TUs for a disconnected
stream
During an atomic commit after all the MST stream CRTC state is computed the driver ensures that the sum of TUs of all the streams on a given MST topology link is within limits (63 for 8b10 and 64 for 128b132b). For a disconnected stream the DRM MST core's BW verification doesn't ensure this, because the topology state it uses for this is destroyed as soon as the stream (i.e. MST connector/port) is disconnected. The driver should keep the link state valid even for such disconnected streams, as userspace may disable them one-by-one only in a deferred way. Ensure the link's sum of TUs stays within limits in this case by simply reusing the maximum link BPP limit from the stream's (i.e. CRTC's) old state.
The disconnection can happen either via the whole topology getting disconnected or via only the given stream's port getting disconnected. Check for both of these conditions separately, as a connector gets unregistered after a link disconnect event only in a deferred way.
drivers/gpu/drm/i915/display/intel_dp_mst.c +21 -0
@@ -2168,6 +2168,27 @@ bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,return false; } +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc) +{ +struct intel_connector *connector; + + connector =get_connector_in_state_for_crtc (state, crtc); +if (!connector) +return false; + +if (!connector->mst.dp) +return false; + +if (!connector->mst.dp->mst.mgr.mst_state) +return true; + +if (drm_connector_is_unregistered (&connector->base)) +return true; + +return false; +} +/** * intel_dp_mst_prepare_probe - Prepare an MST link for topology probing * @intel_dp: DP port object
drivers/gpu/drm/i915/display/intel_dp_mst.h +2 -0
@@ -28,6 +28,8 @@ int intel_dp_mst_atomic_check_link(struct intel_atomic_state *state, struct intel_link_bw_limits *limits);bool intel_dp_mst_crtc_needs_modeset (struct intel_atomic_state *state,struct intel_crtc *crtc); +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc);void intel_dp_mst_prepare_probe (struct intel_dp *intel_dp);bool intel_dp_mst_verify_dpcd_state (struct intel_dp *intel_dp);
drivers/gpu/drm/i915/display/intel_link_bw.c +2 -1
@@ -64,7 +64,8 @@ void intel_link_bw_init_limits(struct intel_atomic_state *state,intel_atomic_get_new_crtc_state (state, crtc);int forced_bpp_x16 =get_forced_link_bpp_x16 (state, crtc); -if (state->base.duplicated && crtc_state) { +if ((state->base.duplicated && crtc_state) || +intel_dp_mst_stream_disconnected (state, crtc)) { limits->max_bpp_x16[pipe] = crtc_state->max_link_bpp_x16;if (intel_dsc_enabled_on_link (crtc_state)) limits->link_dsc_pipes |=BIT (pipe);
Sasha Levin
maintainerPATCH 1/1 drm/i915/dp_mst: Fix configuring TUs for a disconnected stream
From: Imre Deak <[email protected]>
[ Upstream commit a443e0b8d647c1401b110d9f919d8c6cb8607260 ]
During an atomic commit after all the MST stream CRTC state is computed the driver ensures that the sum of TUs of all the streams on a given MST topology link is within limits (63 for 8b10 and 64 for 128b132b). For a disconnected stream the DRM MST core's BW verification doesn't ensure this, because the topology state it uses for this is destroyed as soon as the stream (i.e. MST connector/port) is disconnected. The driver should keep the link state valid even for such disconnected streams, as userspace may disable them one-by-one only in a deferred way. Ensure the link's sum of TUs stays within limits in this case by simply reusing the maximum link BPP limit from the stream's (i.e. CRTC's) old state.
The disconnection can happen either via the whole topology getting disconnected or via only the given stream's port getting disconnected. Check for both of these conditions separately, as a connector gets unregistered after a link disconnect event only in a deferred way.
--- drivers/gpu/drm/i915/display/intel_dp_mst.c | 21 ++++++++++++++++++++ drivers/gpu/drm/i915/display/intel_dp_mst.h | 2 ++ drivers/gpu/drm/i915/display/intel_link_bw.c | 7 ++++--- 3 files changed, 27 insertions(+), 3 deletions(-)
drivers/gpu/drm/i915/display/intel_dp_mst.c +21 -0
@@ -2053,6 +2053,27 @@ bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,return false; } +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc) +{ +struct intel_connector *connector; + + connector =get_connector_in_state_for_crtc (state, crtc); +if (!connector) +return false; + +if (!connector->mst_port) +return false; + +if (!connector->mst_port->mst_mgr.mst_state) +return true; + +if (drm_connector_is_unregistered (&connector->base)) +return true; + +return false; +} +/** * intel_dp_mst_prepare_probe - Prepare an MST link for topology probing * @intel_dp: DP port object
drivers/gpu/drm/i915/display/intel_dp_mst.h +2 -0
@@ -27,6 +27,8 @@ int intel_dp_mst_atomic_check_link(struct intel_atomic_state *state, struct intel_link_bw_limits *limits);bool intel_dp_mst_crtc_needs_modeset (struct intel_atomic_state *state,struct intel_crtc *crtc); +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc);void intel_dp_mst_prepare_probe (struct intel_dp *intel_dp);bool intel_dp_mst_verify_dpcd_state (struct intel_dp *intel_dp);
drivers/gpu/drm/i915/display/intel_link_bw.c +4 -3
@@ -32,11 +32,12 @@ void intel_link_bw_init_limits(struct intel_atomic_state *state, limits->force_fec_pipes =0 ; limits->bpp_limit_reached_pipes =0 ;for_each_pipe (display, pipe) { +struct intel_crtc *crtc =intel_crtc_for_pipe (i915, pipe);const struct intel_crtc_state *crtc_state = -intel_atomic_get_new_crtc_state (state, -intel_crtc_for_pipe (i915, pipe)); +intel_atomic_get_new_crtc_state (state, crtc); -if (state->base.duplicated && crtc_state) { +if ((state->base.duplicated && crtc_state) || +intel_dp_mst_stream_disconnected (state, crtc)) { limits->max_bpp_x16[pipe] = crtc_state->max_link_bpp_x16;if (crtc_state->fec_enable) limits->force_fec_pipes |=BIT (pipe);
Signature · 1 line
2.53.0
Re: [PATCH 6.12.y] drm/i915/dp_mst: Fix configuring TUs for a disconnected stream
Quoted 105 lines · Sasha Levin
From: Imre Deak <[email protected]>
[ Upstream commit
a443e0b8d647c1401b110d9f919d8c6cb8607260]During an atomic commit after all the MST stream CRTC state is computed the driver ensures that the sum of TUs of all the streams on a given MST topology link is within limits (63 for 8b10 and 64 for
128b132b). For a disconnected stream the DRM MST core's BW verification doesn't ensure this, because the topology state it uses for this is destroyed as soon as the stream (i.e. MST connector/port) is disconnected. The driver should keep the link state valid even for such disconnected streams, as userspace may disable them one-by-one only in a deferred way. Ensure the link's sum of TUs stays within limits in this case by simply reusing the maximum link BPP limit from the stream's (i.e. CRTC's) old state.The disconnection can happen either via the whole topology getting disconnected or via only the given stream's port getting disconnected. Check for both of these conditions separately, as a connector gets unregistered after a link disconnect event only in a deferred way.
Cc [email protected] # v6.10+Reviewed-by Luca Coelho <[email protected]>Signed-off-by Imre Deak <[email protected]>(cherry picked from commit ee00f8fbb2b202002ab90834e02e9ba372773a36)Signed-off-by Jani Nikula <[email protected]>[ adapted MST field accesses to `mst_port` and `mst_mgr`, reusing a local `crtc` lookup. ]Signed-off-by Sasha Levin <[email protected]>--- drivers/gpu/drm/i915/display/intel_dp_mst.c | 21 ++++++++++++++++++++ drivers/gpu/drm/i915/display/intel_dp_mst.h | 2 ++ drivers/gpu/drm/i915/display/intel_link_bw.c | 7 ++++--- 3 files changed, 27 insertions(+), 3 deletions(-)drivers/gpu/drm/i915/display/intel_dp_mst.c +21
-0@@ -2053,6 +2053,27 @@ bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,return false; } +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc) +{ +struct intel_connector *connector; + + connector =get_connector_in_state_for_crtc (state, crtc); +if (!connector) +return false; + +if (!connector->mst_port) +return false; + +if (!connector->mst_port->mst_mgr.mst_state) +return true; + +if (drm_connector_is_unregistered (&connector->base)) +return true; + +return false; +} +/** * intel_dp_mst_prepare_probe - Prepare an MST link for topology probing * @intel_dp: DP port object drivers/gpu/drm/i915/display/intel_dp_mst.h +2
-0@@ -27,6 +27,8 @@ int intel_dp_mst_atomic_check_link(struct intel_atomic_state *state, struct intel_link_bw_limits *limits);bool intel_dp_mst_crtc_needs_modeset (struct intel_atomic_state *state,struct intel_crtc *crtc); +bool intel_dp_mst_stream_disconnected (struct intel_atomic_state *state, +const struct intel_crtc *crtc);void intel_dp_mst_prepare_probe (struct intel_dp *intel_dp);bool intel_dp_mst_verify_dpcd_state (struct intel_dp *intel_dp);drivers/gpu/drm/i915/display/intel_link_bw.c +4
-3@@ -32,11 +32,12 @@ void intel_link_bw_init_limits(struct intel_atomic_state *state, limits->force_fec_pipes =0 ; limits->bpp_limit_reached_pipes =0 ;for_each_pipe (display, pipe) { +struct intel_crtc *crtc =intel_crtc_for_pipe (i915, pipe);const struct intel_crtc_state *crtc_state = -intel_atomic_get_new_crtc_state (state, -intel_crtc_for_pipe (i915, pipe)); +intel_atomic_get_new_crtc_state (state, crtc); -if (state->base.duplicated && crtc_state) { +if ((state->base.duplicated && crtc_state) || +intel_dp_mst_stream_disconnected (state, crtc)) { limits->max_bpp_x16[pipe] = crtc_state->max_link_bpp_x16;if (crtc_state->fec_enable) limits->force_fec_pipes |=BIT (pipe);Signature · 1 line
2.53.0
Breaks the build :(