drm/mst: Fix NULL pointer dereference at drm_dp_add_payload_part2

[Why]
Commit:
- commit 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement")
accidently overwrite the commit

drm/mst: Fix NULL pointer dereference at drm_dp_add_payload_part2

[Why]
Commit:
- commit 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement")
accidently overwrite the commit
- commit 54d217406afe ("drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2")
which cause regression.

[How]
Recover the original NULL fix and remove the unnecessary input parameter 'state' for
drm_dp_add_payload_part2().

Fixes: 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement")
Reported-by: Leon Weiß <leon.weiss@ruhr-uni-bochum.de>
Link: https://lore.kernel.org/r/38c253ea42072cc825dc969ac4e6b9b600371cc8.camel@ruhr-uni-bochum.de/
Cc: lyude@redhat.com
Cc: imre.deak@intel.com
Cc: stable@vger.kernel.org
Cc: regressions@lists.linux.dev
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240307062957.2323620-1-Wayne.Lin@amd.com
(cherry picked from commit 4545614c1d8da603e57b60dd66224d81b6ffc305)

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drm/dp_mst: Add drm_dp_mst_aux_for_parent()

Add a function to get the AUX device of the parent of an MST port, used
by a follow-up i915 patch in the patchset.

v2: Move drm_dp_mst_aux_for_parent() f

drm/dp_mst: Add drm_dp_mst_aux_for_parent()

Add a function to get the AUX device of the parent of an MST port, used
by a follow-up i915 patch in the patchset.

v2: Move drm_dp_mst_aux_for_parent() forward declaration to this patch
(Ankit)

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240416221010.376865-10-imre.deak@intel.com

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drm/dp_mst: Factor out drm_dp_mst_port_is_logical()

Factor out a function to check if an MST port is logical, used by a
follow-up i915 patch in the patchset.

v2: Move drm_dp_mst_aux_for_parent() fo

drm/dp_mst: Factor out drm_dp_mst_port_is_logical()

Factor out a function to check if an MST port is logical, used by a
follow-up i915 patch in the patchset.

v2: Move drm_dp_mst_aux_for_parent() forward declaration to the next
patch. (Ankit)

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240416221010.376865-9-imre.deak@intel.com

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drm/mst: read sideband messaging cap

Amend drm_dp_read_mst_cap() to return an enum, indicating "SST", "SST
with sideband messaging", or "MST". Modify all call sites to take the
new return value into

drm/mst: read sideband messaging cap

Amend drm_dp_read_mst_cap() to return an enum, indicating "SST", "SST
with sideband messaging", or "MST". Modify all call sites to take the
new return value into account.

v2:
- Rename enumerators (Ville)

Cc: Arun R Murthy <arun.r.murthy@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b32a3704934871a67d06420b760e148b76c5ced8.1710839496.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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drm/dp_mst: switch from drm_debug_printer() to device specific drm_dbg_printer()

Prefer the device specific debug printer.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Luca Coelh

drm/dp_mst: switch from drm_debug_printer() to device specific drm_dbg_printer()

Prefer the device specific debug printer.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/50d510a6e13735cef10325742bf49b7f6955b970.1705410327.git.jani.nikula@intel.com

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drm/dp_mst: Separate @failing_port list in drm_dp_mst_atomic_check_mgr() comment

Stephen Rothwell reported htmldocs warnings when merging drm-intel
tree:

Documentation/gpu/drm-kms-helpers:296: driv

drm/dp_mst: Separate @failing_port list in drm_dp_mst_atomic_check_mgr() comment

Stephen Rothwell reported htmldocs warnings when merging drm-intel
tree:

Documentation/gpu/drm-kms-helpers:296: drivers/gpu/drm/display/drm_dp_mst_topology.c:5484: ERROR: Unexpected indentation.
Documentation/gpu/drm-kms-helpers:296: drivers/gpu/drm/display/drm_dp_mst_topology.c:5488: WARNING: Block quote ends without a blank line; unexpected unindent.

Separate @failing_port return value list by surrounding it with a
blank line to fix above warnings.

Fixes: 1cd0a5ea427931 ("drm/dp_mst: Factor out a helper to check the atomic state of a topology manager")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20231114141715.6f435118@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231114081033.27343-1-bagasdotme@gmail.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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drm: remove I2C_CLASS_DDC support

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in
olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC.
Class-based device auto

drm: remove I2C_CLASS_DDC support

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in
olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC.
Class-based device auto-detection is a legacy mechanism and shouldn't
be used in new code. So we can remove this class completely now.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

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drm/dp_mst: Fix PBN divider calculation for UHBR rates

The current way of calculating the pbn_div value, the link BW per each
MTP slot, worked only for DP 1.4 link rates. Fix things up for UHBR
rate

drm/dp_mst: Fix PBN divider calculation for UHBR rates

The current way of calculating the pbn_div value, the link BW per each
MTP slot, worked only for DP 1.4 link rates. Fix things up for UHBR
rates calculating with the correct channel coding efficiency based on
the link rate.

v2:
- Return the fractional pbn_div value from drm_dp_get_vc_payload_bw().
v3:
- Fix rounding up quotient while calculating req_slots. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231117150929.1767227-1-imre.deak@intel.com

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drm/dp_mst: Store the MST PBN divider value in fixed point format

On UHBR links the PBN divider is a fractional number, accordingly store
it in fixed point format. For now drm_dp_get_vc_payload_bw()

drm/dp_mst: Store the MST PBN divider value in fixed point format

On UHBR links the PBN divider is a fractional number, accordingly store
it in fixed point format. For now drm_dp_get_vc_payload_bw() always
returns a whole number and all callers will use only the integer part of
it which should preserve the current behavior. The next patch will fix
drm_dp_get_vc_payload_bw() for UHBR rates returning a fractional number
for those (also accounting for the channel coding efficiency correctly).

Cc: Lyude Paul <lyude@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Wayne Lin <wayne.lin@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[Rebased changes in dm_helpers_construct_old_payload() on drm-intel-next]
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116131841.1588781-2-imre.deak@intel.com

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drm/dp: Add helpers to calculate the link BW overhead

Add helpers drivers can use to calculate the BW allocation overhead -
due to SSC, FEC, DSC and data alignment on symbol cycles - and the
channel

drm/dp: Add helpers to calculate the link BW overhead

Add helpers drivers can use to calculate the BW allocation overhead -
due to SSC, FEC, DSC and data alignment on symbol cycles - and the
channel coding efficiency - due to the 8b/10b, 128b/132b encoding. On
128b/132b links the FEC overhead is part of the coding efficiency, so
not accounted for in the BW allocation overhead.

The drivers can use these functions to calculate a ratio, controlling
the stream symbol insertion rate of the source device in each SST TU
or MST MTP frame. Drivers can calculate this

m/n = (pixel_data_rate * drm_dp_bw_overhead()) /
(link_data_rate * drm_dp_bw_channel_coding_efficiency())

ratio for a given link and pixel stream and with that the

slots_per_mtp = CEIL(64 * m / n)

allocated slots per MTP for the stream in a link frame and with
that the

pbn = slots_per_mtp * drm_mst_get_pbn_divider()

allocated PBNs for the stream on the MST link path.

Take drm_dp_bw_overhead() into use in drm_dp_calc_pbn_mode(), for
drivers calculating the PBN value directly.

v2:
- Add dockbook description to drm_dp_bw_channel_coding_efficiency().
(LKP).
- Clarify the way m/n ratio is calculated in the commit log.
v3:
- Fix compile breakage for !CONFIG_BACKLIGHT_CLASS_DEVICE. (LKP)
- Account for FEC_PM overhead (+ 0.0015625 %), add comment
with the formula to calculate the total FEC overhead. (Ville)
v4:
- Rename DRM_DP_OVERHEAD_SSC to DRM_DP_OVERHEAD_SSC_REF_CLK. (Ville)
v5:
- Clarify in the commit log what MTP means.
- Simplify the commit log's formula to calculate PBN.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: kernel test robot <lkp@intel.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v2)
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107001505.3370108-1-imre.deak@intel.com

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drm/dp_mst: Allow DSC in any Synaptics last branch device

The Synaptics MST branch devices support DSC decompression on all their
output ports, provided that they are last branch devices (with their

drm/dp_mst: Allow DSC in any Synaptics last branch device

The Synaptics MST branch devices support DSC decompression on all their
output ports, provided that they are last branch devices (with their
output ports connected to the sinks). The Thinkpad 40B0 TBT dock for
instance has two such branch devices, a secondary one connected to one
of the output ports of the primary; hence the decompression needs to be
enabled in both branch devices to enable decompression for all the
sinks.

Based on the above add support for enabling decompression in last
Synaptics branch devices.

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-7-imre.deak@intel.com

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drm/dp_mst: Swap the order of checking root vs. non-root port BW limitations

drm_dp_mst_atomic_check_mgr() should check for BW limitation starting
from sink ports continuing towards the root port, s

drm/dp_mst: Swap the order of checking root vs. non-root port BW limitations

drm_dp_mst_atomic_check_mgr() should check for BW limitation starting
from sink ports continuing towards the root port, so that drivers can
use the @failing_port returned to resolve a BW overallocation in an
ideal way. For instance from streams A,B,C in a topology A,B going
through @failing_port and C not going through it, a BW overallocation of
A,B due to a limit of the port must be resolved first before considering
the limits of other ports closer to the root port. This way can avoid
reducing the BW of stream C unnecessarily due to a BW limit closer to the
root port.

Based on the above swap the order of the BW check for the root port and
the check for all the ports downstream of it (the latter going through
the topology already in the sink->root port direction).

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-6-imre.deak@intel.com

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drm/dp_mst: Factor out a helper to check the atomic state of a topology manager

Factor out a helper to check the atomic state for one MST topology
manager, returning the MST port where the BW limit

drm/dp_mst: Factor out a helper to check the atomic state of a topology manager

Factor out a helper to check the atomic state for one MST topology
manager, returning the MST port where the BW limit check has failed.
This will be used in a follow-up patch by the i915 driver to improve the
BW sharing between MST streams.

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-5-imre.deak@intel.com

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drm/dp_mst: Add helper to determine if an MST port is downstream of another port

Add drm_dp_mst_port_downstream_of_parent() required by the i915
driver in a follow-up patch to resolve a BW overalloc

drm/dp_mst: Add helper to determine if an MST port is downstream of another port

Add drm_dp_mst_port_downstream_of_parent() required by the i915
driver in a follow-up patch to resolve a BW overallocation of MST
streams going through a given MST port.

Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-4-imre.deak@intel.com

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drm/dp_mst: Fix fractional DSC bpp handling

The current code does '(bpp << 4) / 16' in the MST PBN
calculation, but that is just the same as 'bpp' so the
DSC codepath achieves absolutely nothing. Fi

drm/dp_mst: Fix fractional DSC bpp handling

The current code does '(bpp << 4) / 16' in the MST PBN
calculation, but that is just the same as 'bpp' so the
DSC codepath achieves absolutely nothing. Fix it up so that
the fractional part of the bpp value is actually used instead
of truncated away. 64*1006 has enough zero lsbs that we can
just shift that down in the dividend and thus still manage
to stick to a 32bit divisor.

And while touching this, let's just make the whole thing more
straightforward by making the passed in bpp value .4 binary
fixed point always, instead of having to pass in different
things based on whether DSC is enabled or not.

v2:
- Fix DSC kunit test cases.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: David Francis <David.Francis@amd.com>
Cc: Mikita Lipski <mikita.lipski@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Fixes: dc48529fb14e ("drm/dp_mst: Add PBN calculation for DSC modes")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[Imre: Fix kunit test cases]
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-3-imre.deak@intel.com

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drm/dp_mst: Fix NULL deref in get_mst_branch_device_by_guid_helper()

As drm_dp_get_mst_branch_device_by_guid() is called from
drm_dp_get_mst_branch_device_by_guid(), mstb parameter has to be checked

drm/dp_mst: Fix NULL deref in get_mst_branch_device_by_guid_helper()

As drm_dp_get_mst_branch_device_by_guid() is called from
drm_dp_get_mst_branch_device_by_guid(), mstb parameter has to be checked,
otherwise NULL dereference may occur in the call to
the memcpy() and cause following:

[12579.365869] BUG: kernel NULL pointer dereference, address: 0000000000000049
[12579.365878] #PF: supervisor read access in kernel mode
[12579.365880] #PF: error_code(0x0000) - not-present page
[12579.365882] PGD 0 P4D 0
[12579.365887] Oops: 0000 [#1] PREEMPT SMP NOPTI
...
[12579.365895] Workqueue: events_long drm_dp_mst_up_req_work
[12579.365899] RIP: 0010:memcmp+0xb/0x29
[12579.365921] Call Trace:
[12579.365927] get_mst_branch_device_by_guid_helper+0x22/0x64
[12579.365930] drm_dp_mst_up_req_work+0x137/0x416
[12579.365933] process_one_work+0x1d0/0x419
[12579.365935] worker_thread+0x11a/0x289
[12579.365938] kthread+0x13e/0x14f
[12579.365941] ? process_one_work+0x419/0x419
[12579.365943] ? kthread_blkcg+0x31/0x31
[12579.365946] ret_from_fork+0x1f/0x30

As get_mst_branch_device_by_guid_helper() is recursive, moving condition
to the first line allow to remove a similar one for step over of NULL elements
inside a loop.

Fixes: 5e93b8208d3c ("drm/dp/mst: move GUID storage from mgr, port to only mst branch")
Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Lukasz Majczak <lma@semihalf.com>
Reviewed-by: Radoslaw Biernacki <rad@chromium.org>
Signed-off-by: Manasi Navare <navaremanasi@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230922063410.23626-1-lma@semihalf.com

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drm/dp_mst: Tune down error message during payload addition

If a sink is removed in the middle of payload addition the corresponding
AUX transfer will fail as expected, so tune the error message dow

drm/dp_mst: Tune down error message during payload addition

If a sink is removed in the middle of payload addition the corresponding
AUX transfer will fail as expected, so tune the error message down to a
debug messge.

Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230913223218.540365-3-imre.deak@intel.com

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drm/dp_mst: Sanitize error return during payload addition

Return an error during payload addition if the payload port isn't
found. This shouldn't change the behavior since only the i915 driver
check

drm/dp_mst: Sanitize error return during payload addition

Return an error during payload addition if the payload port isn't
found. This shouldn't change the behavior since only the i915 driver
checks the return value, printing an error message in case of a failure.

While at it simplify the control flow.

Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230913223218.540365-2-imre.deak@intel.com

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drm/dp_mst: Fix NULL dereference during payload addition

Fix the NULL dereference leading to the following stack trace:

[ 129.687181] i915 0000:00:02.0: [drm:drm_dp_add_payload_part1 [drm_display_

drm/dp_mst: Fix NULL dereference during payload addition

Fix the NULL dereference leading to the following stack trace:

[ 129.687181] i915 0000:00:02.0: [drm:drm_dp_add_payload_part1 [drm_display_helper]] VCPI 1 for port 000000005be4423e not in topology, not creating a payload to remote
[ 129.687257] BUG: kernel NULL pointer dereference, address: 0000000000000560
[ 129.694276] #PF: supervisor read access in kernel mode
[ 129.699459] #PF: error_code(0x0000) - not-present page
[ 129.704612] PGD 0 P4D 0
[ 129.707178] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 129.711556] CPU: 2 PID: 1623 Comm: Xorg Tainted: G U 6.6.0-rc1-imre+ #985
[ 129.719744] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR5 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[ 129.732509] RIP: 0010:drm_dp_mst_topology_put_port+0x19/0x170 [drm_display_helper]
[ 129.740111] Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 89 fb 48 83 ec 08 <48> 8b 87 60 05 00 00 44 8b 0f 48 8b 70 58 41 83 e9 01 48 85 f6 74
[ 129.758842] RSP: 0018:ffffc90001daf900 EFLAGS: 00010286
[ 129.764104] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
[ 129.771246] RDX: 0000000000000000 RSI: ffffffff9e73d613 RDI: 0000000000000000
[ 129.778394] RBP: ffffc90001daf930 R08: 0000000000000000 R09: 0000000000000020
[ 129.785533] R10: 0000000000ffff10 R11: 000000000000000f R12: ffff888116c65e40
[ 129.792680] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 129.799822] FS: 00007f39f74b1a80(0000) GS:ffff88840f680000(0000) knlGS:0000000000000000
[ 129.807913] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 129.813670] CR2: 0000000000000560 CR3: 0000000138b88000 CR4: 0000000000750ee0
[ 129.820815] PKRU: 55555554
[ 129.823551] Call Trace:
[ 129.826022] <TASK>
[ 129.828154] ? show_regs+0x65/0x70
[ 129.831599] ? __die+0x24/0x70
[ 129.834683] ? page_fault_oops+0x160/0x480
[ 129.838824] ? dev_printk_emit+0x83/0xb0
[ 129.842797] ? do_user_addr_fault+0x2e2/0x680
[ 129.847175] ? exc_page_fault+0x78/0x180
[ 129.851143] ? asm_exc_page_fault+0x27/0x30
[ 129.855353] ? drm_dp_mst_topology_put_port+0x19/0x170 [drm_display_helper]
[ 129.862354] drm_dp_add_payload_part1+0x85/0x100 [drm_display_helper]
[ 129.868832] intel_mst_pre_enable_dp+0x1ef/0x240 [i915]
[ 129.874170] intel_encoders_pre_enable+0x83/0xa0 [i915]
[ 129.879524] hsw_crtc_enable+0xbe/0x750 [i915]
[ 129.884095] intel_enable_crtc+0x68/0xa0 [i915]
[ 129.888752] skl_commit_modeset_enables+0x2c4/0x5d0 [i915]
[ 129.894365] intel_atomic_commit_tail+0x765/0x1070 [i915]
[ 129.899885] intel_atomic_commit+0x3ba/0x400 [i915]
[ 129.904892] drm_atomic_commit+0x96/0xd0 [drm]
[ 129.909405] ? __pfx___drm_printfn_info+0x10/0x10 [drm]
[ 129.914698] drm_atomic_helper_set_config+0x7e/0xc0 [drm_kms_helper]
[ 129.921102] drm_mode_setcrtc+0x5af/0x8d0 [drm]
[ 129.925695] ? __pfx_drm_mode_setcrtc+0x10/0x10 [drm]
[ 129.930810] drm_ioctl_kernel+0xc4/0x170 [drm]
[ 129.935317] drm_ioctl+0x2a4/0x520 [drm]
[ 129.939305] ? __pfx_drm_mode_setcrtc+0x10/0x10 [drm]
[ 129.944415] ? __fget_light+0xa5/0x110
[ 129.948212] __x64_sys_ioctl+0x98/0xd0
[ 129.951985] do_syscall_64+0x37/0x90
[ 129.955581] entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fixes: 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement")
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230913223218.540365-1-imre.deak@intel.com

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drm/mst: Refactor the flow for payload allocation/removement

[Why]
Today, the allocation/deallocation steps and status is a bit unclear.

For instance, payload->vc_start_slot = -1 stands for "the fa

drm/mst: Refactor the flow for payload allocation/removement

[Why]
Today, the allocation/deallocation steps and status is a bit unclear.

For instance, payload->vc_start_slot = -1 stands for "the failure of
updating DPCD payload ID table" and can also represent as "payload is not
allocated yet". These two cases should be handled differently and hence
better to distinguish them for better understanding.

[How]
Define enumeration - ALLOCATION_LOCAL, ALLOCATION_DFP and ALLOCATION_REMOTE
to distinguish different allocation status. Adjust the code to handle
different status accordingly for better understanding the sequence of
payload allocation and payload removement.

For payload creation, the procedure should look like this:
DRM part 1:
* step 1 - update sw mst mgr variables to add a new payload
* step 2 - add payload at immediate DFP DPCD payload table

Driver:
* Add new payload in HW and sync up with DFP by sending ACT

DRM Part 2:
* Send ALLOCATE_PAYLOAD sideband message to allocate bandwidth along the
virtual channel.

And as for payload removement, the procedure should look like this:
DRM part 1:
* step 1 - Send ALLOCATE_PAYLOAD sideband message to release bandwidth
along the virtual channel
* step 2 - Clear payload allocation at immediate DFP DPCD payload table

Driver:
* Remove the payload in HW and sync up with DFP by sending ACT

DRM part 2:
* update sw mst mgr variables to remove the payload

Note that it's fine to fail when communicate with the branch device
connected at immediate downstrean-facing port, but updating variables of
SW mst mgr and HW configuration should be conducted anyway. That's because
it's under commit_tail and we need to complete the HW programming.

Changes since v1:
* Remove the set but not use variable 'old_payload' in function
'nv50_msto_prepare'. Catched by kernel test robot <lkp@intel.com>

Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807025639.1612361-3-Wayne.Lin@amd.com

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drm/mst: delete unnecessary case in drm_dp_add_payload_part2()

[Why]
There is no need to consider payload->delete case since we won't call
drm_dp_add_payload_part2() to create a payload when we're a

drm/mst: delete unnecessary case in drm_dp_add_payload_part2()

[Why]
There is no need to consider payload->delete case since we won't call
drm_dp_add_payload_part2() to create a payload when we're about to
remove it.

[How]
Delete unnecessary case to simplify the code.

Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807025639.1612361-2-Wayne.Lin@amd.com

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drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2

I've been experiencing some intermittent crashes down in the display
driver code. The symptoms are ususally a line like this in dmesg:

drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2

I've been experiencing some intermittent crashes down in the display
driver code. The symptoms are ususally a line like this in dmesg:

amdgpu 0000:30:00.0: [drm] Failed to create MST payload for port 000000006d3a3885: -5

...followed by an Oops due to a NULL pointer dereference.

Switch to using mgr->dev instead of state->dev since "state" can be
NULL in some cases.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2184855
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230419112447.18471-1-jlayton@kernel.org

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drm/dp_mst: Clear MSG_RDY flag before sending new message

[Why]
The sequence for collecting down_reply from source perspective should
be:

Request_n->repeat (get partial reply of Request_n->clear me

drm/dp_mst: Clear MSG_RDY flag before sending new message

[Why]
The sequence for collecting down_reply from source perspective should
be:

Request_n->repeat (get partial reply of Request_n->clear message ready
flag to ack DPRX that the message is received) till all partial
replies for Request_n are received->new Request_n+1.

Now there is chance that drm_dp_mst_hpd_irq() will fire new down
request in the tx queue when the down reply is incomplete. Source is
restricted to generate interveleaved message transactions so we should
avoid it.

Also, while assembling partial reply packets, reading out DPCD DOWN_REP
Sideband MSG buffer + clearing DOWN_REP_MSG_RDY flag should be
wrapped up as a complete operation for reading out a reply packet.
Kicking off a new request before clearing DOWN_REP_MSG_RDY flag might
be risky. e.g. If the reply of the new request has overwritten the
DPRX DOWN_REP Sideband MSG buffer before source writing one to clear
DOWN_REP_MSG_RDY flag, source then unintentionally flushes the reply
for the new request. Should handle the up request in the same way.

[How]
Separete drm_dp_mst_hpd_irq() into 2 steps. After acking the MST IRQ
event, driver calls drm_dp_mst_hpd_irq_send_new_request() and might
trigger drm_dp_mst_kick_tx() only when there is no on going message
transaction.

Changes since v1:
* Reworked on review comments received
-> Adjust the fix to let driver explicitly kick off new down request
when mst irq event is handled and acked
-> Adjust the commit message

Changes since v2:
* Adjust the commit message
* Adjust the naming of the divided 2 functions and add a new input
parameter "ack".
* Adjust code flow as per review comments.

Changes since v3:
* Update the function description of drm_dp_mst_hpd_irq_handle_event

Changes since v4:
* Change ack of drm_dp_mst_hpd_irq_handle_event() to be an array align
the size of esi[]

Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/display/dp_mst: convert to struct drm_edid

Convert the topology manager to use struct drm_edid, add
drm_dp_mst_edid_read() that returns drm_edid, and rewrite the old
drm_dp_mst_get_edid() to use

drm/display/dp_mst: convert to struct drm_edid

Convert the topology manager to use struct drm_edid, add
drm_dp_mst_edid_read() that returns drm_edid, and rewrite the old
drm_dp_mst_get_edid() to use it.

Note that the old drm_get_edid() ended up calling
drm_connector_update_edid_property(). This responsibility is now
deferred to drivers, which all do it anyway after calling
drm_dp_mst_edid_read() or drm_dp_mst_get_edid().

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9c32e5c241934093fc4144eed4c01155e1f03af1.1685437501.git.jani.nikula@intel.com

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drm/display/dp_mst: drop has_audio from struct drm_dp_mst_port

Caching the has_audio in struct drm_dp_mst_port seems odd, and oddly
placed. Defer audio handling to drivers, and use the info from the

drm/display/dp_mst: drop has_audio from struct drm_dp_mst_port

Caching the has_audio in struct drm_dp_mst_port seems odd, and oddly
placed. Defer audio handling to drivers, and use the info from the
connector display info. i915 was the only one using it anyway.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7d9eefdf150870479c5797f027d4c2b0a19ff583.1685437500.git.jani.nikula@intel.com

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