drm/amd/display: Fix division by zero in setup_dsc_config

When slice_height is 0, the division by slice_height in the calculation
of the number of slices will cause a division by zero driver crash.

drm/amd/display: Fix division by zero in setup_dsc_config

When slice_height is 0, the division by slice_height in the calculation
of the number of slices will cause a division by zero driver crash. This
leaves the kernel in a state that requires a reboot. This patch adds a
check to avoid the division by zero.

The stack trace below is for the 6.8.4 Kernel. I reproduced the issue on
a Z16 Gen 2 Lenovo Thinkpad with a Apple Studio Display monitor
connected via Thunderbolt. The amdgpu driver crashed with this exception
when I rebooted the system with the monitor connected.

kernel: ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447)
kernel: ? do_trap (arch/x86/kernel/traps.c:113 arch/x86/kernel/traps.c:154)
kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu
kernel: ? do_error_trap (./arch/x86/include/asm/traps.h:58 arch/x86/kernel/traps.c:175)
kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu
kernel: ? exc_divide_error (arch/x86/kernel/traps.c:194 (discriminator 2))
kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu
kernel: ? asm_exc_divide_error (./arch/x86/include/asm/idtentry.h:548)
kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu
kernel: dc_dsc_compute_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1109) amdgpu

After applying this patch, the driver no longer crashes when the monitor
is connected and the system is rebooted. I believe this is the same
issue reported for 3113.

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Jose Fernandez <josef@netflix.com>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3113
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Fix compiler warnings on high compiler warning levels

[why]
Enabling higher compiler warning levels results in many issues that can
be trivially resolved as well as some potentially

drm/amd/display: Fix compiler warnings on high compiler warning levels

[why]
Enabling higher compiler warning levels results in many issues that can
be trivially resolved as well as some potentially critical issues.

[how]
Fix all compiler warnings found with various compilers and higher
warning levels. Primarily, potentially uninitialized variables and
unreachable code.

Reviewed-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Fix timing bandwidth calculation for HDMI

[Why && How]
The current bandwidth calculation for timing doesn't account for
certain HDMI modes overhead which leads to DSC can't be enabl

drm/amd/display: Fix timing bandwidth calculation for HDMI

[Why && How]
The current bandwidth calculation for timing doesn't account for
certain HDMI modes overhead which leads to DSC can't be enabled.
Add support to calculate the actual bandwidth for these HDMI modes.

Reviewed-by: Chris Park <chris.park@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Leo (Hanghong) Ma <hanghong.ma@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Add DSC granular throughput adjustment

[Why/How]
Update DSC DPCD parsing to take granular throughput adjustment into
consideration.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
A

drm/amd/display: Add DSC granular throughput adjustment

[Why/How]
Update DSC DPCD parsing to take granular throughput adjustment into
consideration.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Allow 16 max_slices for DP2 DSC

Enable 12 and 16 max_slices for DP2 DSC

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Fangzhi

drm/amd/display: Allow 16 max_slices for DP2 DSC

Enable 12 and 16 max_slices for DP2 DSC

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Add link encoding to timing BW calculation parameters

[Why]
There certain cases where the timing BW is dependent on the type of link
encoding in use. Thus to calculate the correct B

drm/amd/display: Add link encoding to timing BW calculation parameters

[Why]
There certain cases where the timing BW is dependent on the type of link
encoding in use. Thus to calculate the correct BW required for a given
timing, the link encoding should be added as a parameter.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Alan Liu <haoping.liu@amd.com>
Signed-off-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Add stream overhead in BW calculations for 128b/132b

[Why]
Current BW calculations do not account for the additional padding added
for uncompressed pixel-to-symbol packing.

This re

drm/amd/display: Add stream overhead in BW calculations for 128b/132b

[Why]
Current BW calculations do not account for the additional padding added
for uncompressed pixel-to-symbol packing.

This results in X.Y being too low for 128b/132b SST streams in certain
scenarios. If X.Y is too low, end user can observe image corruption.

[How]
Add function to calculate stream overhead to timing BW calculation for
128b/132b SST cases.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Alan Liu <haoping.liu@amd.com>
Signed-off-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: drop redundant memset() in get_available_dsc_slices()

get_available_dsc_slices() returns the number of indices set, and all of
the users of get_available_dsc_slices() don't cross th

drm/amd/display: drop redundant memset() in get_available_dsc_slices()

get_available_dsc_slices() returns the number of indices set, and all of
the users of get_available_dsc_slices() don't cross the returned bound
when iterating over available_slices[]. So, the memset() in
get_available_dsc_slices() is redundant and can be dropped.

Fixes: 97bda0322b8a ("drm/amd/display: Add DSC support for Navi (v2)")
Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: DSC policy override when ODM combine is forced

[why]
When we force ODM combine with DSC, we lose several
8 bit and 10 bit modes in validation and thus
not able to use HDR. This is d

drm/amd/display: DSC policy override when ODM combine is forced

[why]
When we force ODM combine with DSC, we lose several
8 bit and 10 bit modes in validation and thus
not able to use HDR. This is due to the number of
horizontal slices used in DSC not properly being
accounted for currently when 2:1 ODM Combine is forced.

[how]
Enforce at least two horizontal slices are used for DSC when
ODM combine is forced.

Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Nasir Osman <nasir.osman@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: convert link.h functions to function pointer style

[Why & How]
All dc subcomponents should call another dc component via function pointers
stored in a component structure. This is p

drm/amd/display: convert link.h functions to function pointer style

[Why & How]
All dc subcomponents should call another dc component via function pointers
stored in a component structure. This is part of dc coding convention since
the beginning. The reason behind this is to improve encapsulation and
polymorphism. The function contract is extracted into a single link service
structure defined in link.h header file and implemented only in link_factory.c instead
of spreading across multiple files in link component file structure.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: fix typo in dc_dsc_config_options structure

[WHY]
There is a typo in dc_dsc_config_options structure

[HOW]
Fix the typo

Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Qi

drm/amd/display: fix typo in dc_dsc_config_options structure

[WHY]
There is a typo in dc_dsc_config_options structure

[HOW]
Fix the typo

Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Mike Hsieh <Mike.Hsieh@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Add height granularity limitation for dsc slice height calculation

[WHY]
eDP add new limitation for Y granularity for selected update feature.
DSC does not include this limitation w

drm/amd/display: Add height granularity limitation for dsc slice height calculation

[WHY]
eDP add new limitation for Y granularity for selected update feature.
DSC does not include this limitation while calculating slice height.

[HOW]
Add new limitation while looking for DSC slice height.

Reviewed-by: Cruise Hung <Cruise.Hung@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Mike Hsieh <Mike.Hsieh@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd: Fix spelling typo in comments

Fix spelling typo in comments.

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: pengfuyuan <pengfuyuan@kylinos.cn>
Signed-off-by: Alex Deucher <alexan

drm/amd: Fix spelling typo in comments

Fix spelling typo in comments.

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: pengfuyuan <pengfuyuan@kylinos.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/display: Move DSC header and helpers into display-helper module

DSC is the Display Stream Compression standard for DisplayPort. Move
the DSC code into display/ and split the header into files fo

drm/display: Move DSC header and helpers into display-helper module

DSC is the Display Stream Compression standard for DisplayPort. Move
the DSC code into display/ and split the header into files for protocol
core and DRM helpers. Adapt all users of the code. No functional
changes.

To avoid the proliferation of Kconfig options, DSC is part of DRM's
support for DisplayPort. If necessary, a new option could make DSC an
independent feature.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-6-tzimmermann@suse.de

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drm: Rename dp/ to display/

Rename dp/ to display/ to account for additional display-related
helpers, such as HDMI. Update all related include statements. No
functional changes.

Various drivers, su

drm: Rename dp/ to display/

Rename dp/ to display/ to account for additional display-related
helpers, such as HDMI. Update all related include statements. No
functional changes.

Various drivers, such as i915 and amdgpu, use similar naming scheme
by putting code for video-output standards into a local display/
directory. The new directory's name is aligned with this convention.

v2:
* update commit message (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-3-tzimmermann@suse.de

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drm/amd/display: Correct Slice reset calculation

[Why]
Once DSC slice cannot fit pixel clock, we incorrectly
reset min slices to 0 and allow max slice to operate,
even when max slice itself cannot f

drm/amd/display: Correct Slice reset calculation

[Why]
Once DSC slice cannot fit pixel clock, we incorrectly
reset min slices to 0 and allow max slice to operate,
even when max slice itself cannot fit the pixel clock
properly.

[How]
Change the sequence such that we correctly determine
DSC is not possible when both min slices and max
slices cannot fit pixel clock per slice.

Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Chris Park <Chris.Park@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/dp: Move public DisplayPort headers into dp/

Move all public DisplayPort headers into dp/ and update users. No
functional changes.

v3:
* rebased onto latest drm-tip

Signed-off-by: Thomas Zimm

drm/dp: Move public DisplayPort headers into dp/

Move all public DisplayPort headers into dp/ and update users. No
functional changes.

v3:
* rebased onto latest drm-tip

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114114535.29157-5-tzimmermann@suse.de

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drm/amd/display: Enable DSC over eDP

[why]
- Adding a DM interface to enable DSC over eDP on Linux
- DSC over eDP will allow to power savings by reducing
the bandwidth required to support panel's mo

drm/amd/display: Enable DSC over eDP

[why]
- Adding a DM interface to enable DSC over eDP on Linux
- DSC over eDP will allow to power savings by reducing
the bandwidth required to support panel's modes
- Apply link optimization algorithm to reduce link bandwidth
when DSC is enabled

[how]
- Read eDP panel's DSC capabilities
- Apply DSC policy on eDP panel based on its DSC capabilities
- Enable DSC encoder's on the pipe
- Enable DSC on panel's side by setting DSC_ENABLE DPCD register
- Adding link optimization algorithm to reduce link rate or lane
count based

Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Fix Coverity Issues

[Why]
Coverity discovers holes in logic that needs to be addressed for
improved code integrity.

[How]
Address issues found by coverity without changing the actu

drm/amd/display: Fix Coverity Issues

[Why]
Coverity discovers holes in logic that needs to be addressed for
improved code integrity.

[How]
Address issues found by coverity without changing the actual logic.

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Chris Park <Chris.Park@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: move bpp range decision in decide dsc bw range function

[why]
Before get dsc bw range is used to compute DSC bw range
based on the given fixed bpp min/max input.
The new change will

drm/amd/display: move bpp range decision in decide dsc bw range function

[why]
Before get dsc bw range is used to compute DSC bw range
based on the given fixed bpp min/max input.
The new change will merge any specs, signal, timing specific
bpp range decision into this function. So the function needs to make
a decision with all aspects considered.

Acked-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: expose dsc overhead bw in dc dsc header

[why]
DM needs to know how much overhead is added to DSC as result
of AMD internal DSC limitation.

Acked-by: Mikita Lipski <mikita.lipski@am

drm/amd/display: expose dsc overhead bw in dc dsc header

[why]
DM needs to know how much overhead is added to DSC as result
of AMD internal DSC limitation.

Acked-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Fixed EdidUtility build errors

[HOW]
Added #ifdefs and refactored various parts of dc to
allow dc_link to be built by AMD EDID UTILITY

[WHY]
dc_dsc was refactored moving some of th

drm/amd/display: Fixed EdidUtility build errors

[HOW]
Added #ifdefs and refactored various parts of dc to
allow dc_link to be built by AMD EDID UTILITY

[WHY]
dc_dsc was refactored moving some of the code that AMD EDID UTILITY needed
to dc_link, so now dc_link needs to be included by AMD EDID UTILITY

Squash in DCN config fix (Alex)

Reviewed-by: Leung Martin <Martin.Leung@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Mark Morra <MarkAlbert.Morra@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: add dsc stream overhead for dp only

[why]
Based on hardware team recommendation this additional dsc overhead
is only required for DP DSC.

[how]
Add a check for is_dp and only apply

drm/amd/display: add dsc stream overhead for dp only

[why]
Based on hardware team recommendation this additional dsc overhead
is only required for DP DSC.

[how]
Add a check for is_dp and only apply the overhead if this flag is set.

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: Chris Park <Chris.Park@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: take max dsc stream bandwidth overhead into account

[why]
As hardware team suggested that we need to add a max dsc bw overhead
into existing stream bandwidth when DSC is used.
The f

drm/amd/display: take max dsc stream bandwidth overhead into account

[why]
As hardware team suggested that we need to add a max dsc bw overhead
into existing stream bandwidth when DSC is used.
The formula as below:

max_dsc_bw_overhead =
v_addressable * slice_count * 256 bit * pixel clock / v_total / h_total

effective stream bandwidth = pixel clock * bpp

stream bandwidth = effective stream bandwidth + dsc stream overhead

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: Eric Bernstein <Eric.Bernstein@amd.com>
Acked-by: Wayne Lin <waynelin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Add changes for dsc bpp in 16ths and unify bw calculations

[Why?]
Some code still expected bpp to be used in whole bits, not 16ths. dsc.c uses
redundant function now found in dc to

drm/amd/display: Add changes for dsc bpp in 16ths and unify bw calculations

[Why?]
Some code still expected bpp to be used in whole bits, not 16ths. dsc.c uses
redundant function now found in dc to calculate stream bandwidth from timing.

[How?]
Fix code to work with 16ths instead of whole bits for dsc bpp.
Refactor get_dsc_bandwidth to accept inputs in 16ths of a bit.
Use dc function to calculate bandwidth from timing, and make dsc bw calculation
a part of dsc.c.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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