GCC reports the following warning with W=1:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_psr.c:70:13:
warning:
variable ‘dc’ set but not used [-Wunused-but-set-variable]
70 | struct dc *dc = NULL;
| ^~
This variable is not used in function, this commit remove it to
fix the warning.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
GCC reports the following warning with W=1:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:3635:17:
warning:
variable ‘status’ set but not used [-Wunused-but-set-variable]
3635 | enum dc_status status = DC_ERROR_UNEXPECTED;
| ^~~~~~
The variable should be used for error check, let's fix it.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Recently, we added support for an experimental feature named Freesync
video; for more details on that, refer to:
commit 6f59f229f8 ("drm/amd/display: Skip modeset for front porch change")
commit d10cd527f5 ("drm/amd/display: Add freesync video modes based on preferred modes")
commit 0eb1af2e82 ("drm/amd/display: Add module parameter for freesync video mode")
Nevertheless, we did not document it in detail in our driver. This
commit introduces a kernel-doc and expands the module parameter
description.
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Current watermarks end up programming lowers watermarks which
results in screen flickering and underflow for certain modes like 1440p.
[How]
Add 11us to stutter exit & stutter enter plus exit watermark.
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Fix the following coccicheck warning:
drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c:917:56-57:
pstate_enabled: first occurrence line 935, second occurrence line 937
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
DP LL Compliance tests require that the first DPCD transactions after a
hotplug have a timeout interval of 3.2 ms. In cases where LTTPR is
disabled, this means that the first reads from DP_SET_POWER and DP_DPCD_REV must have an extended
timeout.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
When changing the DISPCLK_WDIVIDER value from 126 to 127, the change in
clock rate is too great for the FIFOs to handle. This can cause visible
corruption during clock change.
HW has handed down this register sequence to fix the issue.
[HOW]
The sequence, from HW:
a. 127 -> 126
Read DIG_FIFO_CAL_AVERAGE_LEVEL
FIFO level N = DIG_FIFO_CAL_AVERAGE_LEVEL / 4
Set DCCG_FIFO_ERRDET_OVR_EN = 1
Write 1 to OTGx_DROP_PIXEL for (N-4) times
Set DCCG_FIFO_ERRDET_OVR_EN = 0
Write DENTIST_DISPCLK_RDIVIDER = 126
Because of frequency stepping, sequence a can be executed to change the
divider from 127 to any other divider value.
b. 126 -> 127
Read DIG_FIFO_CAL_AVERAGE_LEVEL
FIFO level N = DIG_FIFO_CAL_AVERAGE_LEVEL / 4
Set DCCG_FIFO_ERRDET_OVR_EN = 1
Write 1 to OTGx_ADD_PIXEL for (12-N) times
Set DCCG_FIFO_ERRDET_OVR_EN = 0
Write DENTIST_DISPCLK_RDIVIDER = 127
Because of frequency stepping, divider must first be set from any other
divider value to 126 before executing sequence b.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
Hardware has handed down a new sequence requiring the value of this
register be read from clk_mgr.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
SCR for DP 2.0 spec says that multiple LTTPRs must not be accessed in a
single AUX transaction.
There may be other places in future where breaking up AUX accesses is
necessary.
[HOW]
Partition the entire DPCD address space into blocks. When an incoming AUX
request spans multiple blocks, break up the request into multiple requests.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
DP 2.0 SCR specifies that
"A DPTX shall distinguish I2C_DEFER|AUX_ACK from AUX_DEFER. AUX retries
due to
I2C_DEFER are not counted as part of minimum 7 retires (sic) upon
AUX_DEFER’s"
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
DP 2.0 SCR specifies that TX devices must retry at least 7 times when
receiving an AUX DEFER reply from RX. In addition, the specification
states that the TX shall not retry indefinitely, and gives a suggestive
timeout interval of 50ms.
[HOW]
Keep retrying until both 7 or more retries have been made, and the 50ms
interval has passed.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
7 is the minimum number of retries TX must attempt on an AUX DEFER, not
the maximum.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
Some DPCD addresses, notably LTTPR Capability registers, are expected to
be read all together in a single DPCD transaction. Rather than force callers to
read registers they don't need, we want to quietly extend the addresses
read, and only return back the values the caller asked for.
This does not affect DPCD writes.
[HOW]
Create an additional layer above AUX to perform 'checked' DPCD
transactions.
Iterate through an array of DPCD address ranges that are marked as being
contiguous. If a requested read falls within one of those ranges, extend
the read to include the entire range.
After DPCD has been queried, copy the requested bytes into the caller's
data buffer, and deallocate all resources used.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
DP specifies that an LTTPR device is only present if PHY_REPEATER_CNT is
0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, or 0x01.
All other values should be considered no LTTPRs present.
[HOW]
Function dp_convert_to_count already does this check. Use it to determine
if PHY_REPEATER_CNT is a valid LTTPR count.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
SCR for DP2.0 requires that LT be performed with PHY_REPEATER_MODE
programmed to 0x55 (Transparent) whenever PHY_REPEATER_CNT is any value
other than 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, or 0x01.
[HOW]
Write Non-Transparent (0xAA) to PHY_REPEATER_MODE when LTTPRs detected and Non-Transparent is
requested.
Write Transparent in all other cases.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
SCR for DP 2.0 Spec states that a DPTX shall put LTTPRs into Transparent
mode after reading LTTPR Capability registers on HPD.
The wording of the SCR is somewhat ambiguous as to whether
Transparent mode must be set explicity, or is implicitly set on LTTPR
capability read. Explicitly setting Transparent mode after LTTPR
capability read should cover all
cases.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
SCR for DP 2.0 requires that LTTPR caps be read first on hotplug.
For the sake of consistency, this should also be the case on bootup.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
We want LTTPR capabilities to be readable from more places than just
retrieve_link_cap
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
A new SCR for the DP2.0 spec requires that LTTPR caps be the first thing
read from DPCD upon hotplug.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Improve the maintain/read abilities of dm code.
[How]
Create amdgpu_dm_psr.c/h files.
Move psr function from amdgpu_dm.c
Signed-off-by: Roman Li <roman.li@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This version brings along following fixed:
- LTTPR improvements
- Backlight improvements
- eDP hotplug detection
Signed-off-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: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
To change the swizzle visual confirm reference pipe from top pipe to
bottom pipe due to bottom pipe information would be more important
for multiple overlay case.
Signed-off-by: Po-Ting Chen <robin.chen@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[why]
Move mst start top mgr in dc_link_detect layer.
Remove unused same_dpcd variable.
Move PEAK_FACTOR_X1000 and LINK_TRAINING_MAX_VERIFY_RETRY
to the proper header for defining dc link internal constant.
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: George Shen <George.Shen@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why & How]
Tune backlight ramping profiles for each Vari-Bright level to suit
customer preferences
Signed-off-by: Josip Pavic <Josip.Pavic@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Some custom platforms use eDP hotplug events to notify panel
capability changes that should be reported
[How]
Add a DC config option that unblocks eDP hotplug events
Signed-off-by: Yi-Ling Chen <Yi-Ling.Chen2@amd.com>
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: Alex Deucher <alexander.deucher@amd.com>
[WHY]
Ability to triage DMCUB is improved with availability of certain
dmub registers not currently captured in crash dump diagnostic data.
[HOW]
Add dmub registers to diagnostic data collection.
Thanks Nicholas Kazlauskas for awesome input on this!
Signed-off-by: Ashley Thomas <Ashley.Thomas2@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
For each CRTC state, check the size of Gamma and Degamma LUTs so
unexpected and larger sizes wouldn't slip through.
TEST: IGT:kms_color::pipe-invalid-gamma-lut-sizes
v2: fix assignments in if clauses, Mark's email.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why&How]
PG registers are absent in beige goby, so programming these registers
generate call trace. Fix this by adding a dummy function in dcn303
initialization function which prevents writing to non existant registers.
Fixes: cd6d421e3d ("drm/amd/display: Initial DC support for Beige Goby")
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Fix the following coccicheck warning:
./drivers/gpu/drm/amd/display/dc/dml/dcn31/display_mode_vba_31.c:
3539:12-42: duplicated argument to && or ||
./drivers/gpu/drm/amd/display/dc/dml/dcn31/display_mode_vba_31.c:
5677:87-123: duplicated argument to && or ||
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Use ARRAY_SIZE instead of dividing sizeof array with sizeof an
element.
Clean up the following coccicheck warning:
./drivers/gpu/drm/amd/display/dc/core/dc_resource.c:448:47-48: WARNING:
Use ARRAY_SIZE.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Clean up the following includecheck warning:
./drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c: clk_mgr.h is
included more than once.
No functional change.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
To support a new visual confirm mode: swizzle to show the specific
color at the screen border according to different surface swizzle mode.
Currently we only support the Linear mode with red color.
Signed-off-by: Po-Ting Chen <robin.chen@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
- Commit from userspace could cause link stream to disable and hdcp
auth to reset when the HDCP has already been enabled at the moment.
CP should fall back to DESIRED from ENABLED in such cases.
- This change was previously reverted due to a regression caused, which
has now been cleared.
[HOW]
In hdcp display removal, change CP to DESIRED if at the moment CP
is ENABLED before the auth reset and removal of linked list element.
Signed-off-by: Dingchen (David) Zhang <dingchen.zhang@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
There is an assert in cases where transition from ODM 2:1
to ODM 1:1 (bypass)
[How]
Remove assert since this case is now valid.
Update diags tests for ODM transitions.
Signed-off-by: Eric Bernstein <eric.bernstein@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Found a use case (IPKVM) that DP-VGA active dongle does
not return any EDID and the mentioned commit broke it.
[How]
This reverts "Disconnect non-DP with no EDID"
Signed-off-by: Roy Chan <roy.chan@amd.com>
Reviewed-by: Chris Park <Chris.Park@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why & How]
Add debugfs entry to force dsc decoding at PCON when DSC capable
external RX is connected. In such case, it is free to test DSC
decoding at external RX or at PCON.
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
When calculating recout width for an MPO plane on a mode that's using
ODM combine, driver can calculate a negative value, resulting in a
crash.
[How]
For negative widths, use zero such that validation will prune the
configuration correctly and disallow MPO.
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
For DCN30 and later, there is no data in DML arrays indexed by state at
index num_states.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
DISPCLK_MAX_ERRDET_CYCLES must be 7 to prevent connection loss when
changing DENTIST_DISPCLK_WDIVIDER from 126 to 127 and back.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
HW has handed down a new sequence that requires access to these
registers.
v2: squash in DCN3.1 fixes (Alex)
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[WHY]
HW has handed down a new sequence which requires access to the FIFO
ERRDET SW Override register.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>