intf_audio_select() callback function use to configure
HDMI_DP_CORE_SELECT to decide audio output routes to HDMI or DP
interface. HDMI is obsoleted at newer chipset. To keep supporting
legacy hdmi application, intf_audio_select call back function have
to be populated base on hardware chip capability where legacy
chipsets have has_audio_select flag set to true.
Changes in V2:
-- remove has_audio_select flag
-- add BIT(DPU_MDP_AUDIO_SELECT) into dpu_mdp_cfg
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/1644875214-12944-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
dpu_core_irq_callback_handler() function comments seem to have become
stale and emit a warning:
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:147:
warning: Function parameter or member 'dpu_kms' not described in 'dpu_core_irq_callback_handler'
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:147:
warning: Excess function parameter 'arg' description in 'dpu_core_irq_callback_handler'
Fix by updating the documentation
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20220210114106.290669-3-vkoul@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
We get warning:
In function ‘dpu_encoder_virt_enable’: drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c:1145:33:
warning: variable ‘priv’ set but not used [-Wunused-but-set-variable]
1145 | struct msm_drm_private *priv;
In function ‘dpu_encoder_virt_disable’: drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c:1182:33:
warning: variable ‘priv’ set but not used [-Wunused-but-set-variable]
1182 | struct msm_drm_private *priv;
Remove these unused but set variables
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20220210114106.290669-1-vkoul@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Quoting the header comments, IRQF_ONESHOT is "Used by threaded interrupts
which need to keep the irq line disabled until the threaded handler has
been run.". When applied to an interrupt that doesn't request a threaded
irq then IRQF_ONESHOT has a lesser known (undocumented?) side effect,
which it to disable the forced threading of irqs. For "normal" kernels
if there is no thread_fn then IRQF_ONESHOT is a nop.
In this case disabling forced threading is not appropriate because the
driver calls wake_up_all() (via msm_hdmi_i2c_irq) and also directly uses
the regular spinlock API for locking (in msm_hdmi_hdcp_irq() ). Neither
of these APIs can be called from no-thread interrupt handlers on
PREEMPT_RT systems.
Fix this by removing IRQF_ONESHOT.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220201174734.196718-3-daniel.thompson@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
The DSI subsystem does not fully fall into the pre-enable/enable system
of callbacks, since typically DSI device bridge drivers expect to be
able to communicate with DSI devices at the pre-enable() callback. The
reason is that for some DSI hosts enabling the video stream would
prevent other drivers from sending DSI commands. For example see the
panel-bridge driver, which does drm_panel_prepare() from the
pre_enable() callback (which would be called before our pre_enable()
callback, resulting in panel preparation failures as the link is not yet
ready).
Therewere several attempts to solve this issue, but currently the best
approach is to power up the DSI link from the mode_set() callback,
allowing next bridge/panel to use DSI transfers in the pre_enable()
time. Follow this approach.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20211207222901.988484-2-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Quoting the header comments, IRQF_ONESHOT is "Used by threaded interrupts
which need to keep the irq line disabled until the threaded handler has
been run.". When applied to an interrupt that doesn't request a threaded
irq then IRQF_ONESHOT has a lesser known (undocumented?) side effect,
which it to disable the forced threading of irqs (and for "normal" kernels
it is a nop). In this case I can find no evidence that suppressing forced
threading is intentional. Had it been intentional then a driver must adopt
the raw_spinlock API in order to avoid deadlocks on PREEMPT_RT kernels
(and avoid calling any kernel API that uses regular spinlocks).
Fix this by removing the spurious additional flag.
This change is required for my Snapdragon 7cx Gen2 tablet to boot-to-GUI
with PREEMPT_RT enabled.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220201174734.196718-2-daniel.thompson@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
All DSI PHY/PLL drivers were referencing their VCO parent clock by a
global name, most of which don't exist or have been renamed. These
clock drivers seem to function fine without that except the 14nm driver
for sdm6xx [1].
At the same time all DTs provide a "ref" clock as per the requirements
of dsi-phy-common.yaml, but the clock is never used. This patchset puts
that clock to use without relying on a global clock name, so that all
dependencies are explicitly defined in DT (the firmware) in the end.
Note that this patch intentionally breaks older firmware (DT) that
relies on the clock to be found globally instead. The only affected
platform is msm8974 [2] for whose dsi_phy_28nm a .name="xo" fallback is
left in place to accommodate a more graceful transition period. All
other platforms had the "ref" clock added to their phy node since its
inception, or in a followup patch some time after. These patches
wrongly assumed that the "ref" clock was actively used and have hence
been listed as "Fixes:" below.
Furthermore apq8064 was providing the wrong 19.2MHz cxo instead of
27MHz pxo clock, which has been addressed in [3].
It is expected that both [2] and [3] are applied to the tree well in
advance of this patch such that any actual breakage is extremely
unlikely, but might still occur if kernel upgrades are performed without
the DT to match. After some time the fallback for msm8974 can be
removed again as well.
[1]: https://lore.kernel.org/linux-arm-msm/386db1a6-a1cd-3c7d-a88e-dc83f8a1be96@somainline.org/
[2]: https://lore.kernel.org/linux-arm-msm/20210830175739.143401-1-marijn.suijten@somainline.org/
[3]: https://lore.kernel.org/linux-arm-msm/20210829203027.276143-2-marijn.suijten@somainline.org/
Fixes: 79e51645a1 ("arm64: dts: qcom: msm8916: Set 'xo_board' as ref clock of the DSI PHY")
Fixes: 6969d1d9c6 ("ARM: dts: qcom-apq8064: Set 'cxo_board' as ref clock of the DSI PHY")
Fixes: 0c0e72705a ("arm64: dts: sdm845: Set 'bi_tcxo' as ref clock of the DSI PHYs")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210911131922.387964-2-marijn.suijten@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Each DP link training contains link training 1 followed by link
training 2. There is maximum of 5 retries of DP link training
before declared link training failed. It is required to stop link
training at end of link training 2 if it is failed so that next
link training 1 can start freshly. This patch fixes link compliance
test case 4.3.1.13 (Source Device Link Training EQ Fallback Test).
Changes in v10:
-- group into one series
Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read
Fixes: 2e0adc765d ("drm/msm/dp: do not end dp link training until video is ready")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-5-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Some DP sinkers prefer to use tps4 instead of tps3 during training #2.
This patch will use tps4 to perform link training #2 if sinker's DPCD
supports it.
Changes in V2:
-- replace dp_catalog_ctrl_set_pattern() with dp_catalog_ctrl_set_pattern_state_bit()
Changes in V3:
-- change state_ctrl_bits type to u32 and pattern type to u8
Changes in V4:
-- align } else if { and } else {
Changes in v10:
-- group into one series
Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-4-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
DP CTS test case 4.2.2.6 has valid edid with bad checksum on purpose
and expect DP source return correct checksum. During drm edid read,
correct edid checksum is calculated and stored at
connector::real_edid_checksum.
The problem is struct dp_panel::connector never be assigned, instead the
connector is stored in struct msm_dp::connector. When we run compliance
testing test case 4.2.2.6 dp_panel_handle_sink_request() won't have a valid
edid set in struct dp_panel::edid so we'll try to use the connectors
real_edid_checksum and hit a NULL pointer dereference error because the
connector pointer is never assigned.
Changes in V2:
-- populate panel connector at msm_dp_modeset_init() instead of at dp_panel_read_sink_caps()
Changes in V3:
-- remove unhelpful kernel crash trace commit text
-- remove renaming dp_display parameter to dp
Changes in V4:
-- add more details to commit text
Changes in v10:
-- group into one series
Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read
Fixes: 7948fe12d4 ("drm/msm/dp: return correct edid checksum after corrupted edid checksum read")
Signee-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-3-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Current DP drivers have regulators, clocks, irq and phy are grouped
together within a function and executed not in a symmetric manner.
This increase difficulty of code maintenance and limited code scalability.
This patch divides the driver life cycle of operation into four states,
resume (including booting up), dongle plugin, dongle unplugged and suspend.
Regulators, core clocks and irq are grouped together and enabled at resume
(or booting up) so that the DP controller is armed and ready to receive HPD
plugin interrupts. HPD plugin interrupt is generated when a dongle plugs
into DUT (device under test). Once HPD plugin interrupt is received, DP
controller will initialize phy so that dpcd read/write will function and
following link training can be proceeded successfully. DP phy will be
disabled after main link is teared down at end of unplugged HPD interrupt
handle triggered by dongle unplugged out of DUT. Finally regulators, code
clocks and irq are disabled at corresponding suspension.
Changes in V2:
-- removed unnecessary dp_ctrl NULL check
-- removed unnecessary phy init_count and power_count DRM_DEBUG_DP logs
-- remove flip parameter out of dp_ctrl_irq_enable()
-- add fixes tag
Changes in V3:
-- call dp_display_host_phy_init() instead of dp_ctrl_phy_init() at
dp_display_host_init() for eDP
Changes in V4:
-- rewording commit text to match this commit changes
Changes in V5:
-- rebase on top of msm-next branch
Changes in V6:
-- delete flip variable
Changes in V7:
-- dp_ctrl_irq_enable/disabe() merged into dp_ctrl_reset_irq_ctrl()
Changes in V8:
-- add more detail comment regrading dp phy at dp_display_host_init()
Changes in V9:
-- remove set phy_initialized to false when -ECONNRESET detected
Changes in v10:
-- group into one series
Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately
if aux read
Changes in v12:
-- move dp_display_host_phy_exit() after dp_display_host_deinit()
Changes in v13:
-- do not execute phy_init until plugged_in interrupt for edp, same as DP.
Changes in v14:
-- remove redundant dp->core_initialized = false form dp_pm_suspend.
Changes in v15:
-- remove core_initialized flag check at both host_init and host_deinit
Changes in v16:
-- remove dp_display_host_phy_exit core_initialized=false at dp_pm_suspend
Changes in v17:
-- remove core_initialized checking before execute attention_cb()
Changes in v18:
-- remove core_initialized checking at dp_pm_suspend
Fixes: 8ede2ecc3e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-2-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In the cleanup path of the MSM DP driver the DP driver's debugfs files
are destroyed by invoking debugfs_remove_recursive() on debug->root,
which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry
needs to be kept track of or the files needs to be put in a subdirectory
which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the
name of the associated connector this also solves the problem that these
names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would
have been to put keep track of the individual files and put them under
the connector's debugfs directory. But while the drm_connector has been
allocated, its associated debugfs directory has not been created at the
time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20211015231702.1784254-1-bjorn.andersson@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cross-subsystem Changes:
------------------------
dma-buf:
- dma-buf-map: Rename to iosys-map (Lucas)
Core Changes:
-------------
drm:
- Always include the debugfs_entry in drm_crtc (Ville)
- Add orientation quirk for GPD Win Max (Anisse)
Driver Changes:
---------------
gvt:
- Constify some pointers. (Rikard Falkeborn)
- Use list_entry to access list members. (Guenter Roeck)
- Fix cmd parser error for Passmark9. (Zhenyu Wang)
i915:
- Various clean-ups including headers and removing unused and unnecessary stuff\
(Jani, Hans, Andy, Ville)
- Cleaning up on our registers definitions i915_reg.h (Matt)
- More multi-FBC refactoring (Ville)
- Baytrail backlight fix (Hans)
- DG1 OPROM read through SPI controller (Clint)
- ADL-N platform enabling (Tejas)
- Fix slab-out-of-bounds access (Jani)
- Add opregion mailbox #5 support for possible EDID override (Anisse)
- Fix possible NULL dereferences (Harish)
- Updates and fixes around display voltage swing values (Clint, Jose)
- Fix RPM wekeref on PXP code (Juston)
- Many register definitions clean-up, including planes registers (Ville)
- More conversion towards display version over the old gen (Madhumitha, Ville)
- DP MST ESI handling improvements (Jani)
- drm device based logging conversions (Jani)
- Prevent divide by zero (Dan)
- Introduce ilk_pch_pre_enable for complete modeset abstraction (Ville)
- Async flip optimization for DG2 (Stanislav)
- Multiple DSC and bigjoiner fixes and improvements (Ville)
- Fix ADL-P TypeC Phy ready status readout (Imre)
- Fix up DP DFP 4:2:0 handling more display related fixes (Ville)
- Display M/N cleanup (Ville)
- Switch to use VGA definitions from video/vga.h (Jani)
- Fixes and improvements to abstract CPU architecture (Lucas)
- Disable unsused power wells left enabled by BIOS (Imre)
- Allow !join_mbus cases for adlp+ dbuf configuration (Ville)
- Populate pipe dbuf slices more accurately during readout (Ville)
- Workaround broken BIOS DBUF configuration on TGL/RKL (Ville)
- Fix trailing semicolon (Lucas)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YgKFLmCgpv4vQEa1@intel.com
Rename struct dma_buf_map to struct iosys_map and corresponding APIs.
Over time dma-buf-map grew up to more functionality than the one used by
dma-buf: in fact it's just a shim layer to abstract system memory, that
can be accessed via regular load and store, from IO memory that needs to
be acessed via arch helpers.
The idea is to extend this API so it can fulfill other needs, internal
to a single driver. Example: in the i915 driver it's desired to share
the implementation for integrated graphics, which uses mostly system
memory, with discrete graphics, which may need to access IO memory.
The conversion was mostly done with the following semantic patch:
@r1@
@@
- struct dma_buf_map
+ struct iosys_map
@r2@
@@
(
- DMA_BUF_MAP_INIT_VADDR
+ IOSYS_MAP_INIT_VADDR
|
- dma_buf_map_set_vaddr
+ iosys_map_set_vaddr
|
- dma_buf_map_set_vaddr_iomem
+ iosys_map_set_vaddr_iomem
|
- dma_buf_map_is_equal
+ iosys_map_is_equal
|
- dma_buf_map_is_null
+ iosys_map_is_null
|
- dma_buf_map_is_set
+ iosys_map_is_set
|
- dma_buf_map_clear
+ iosys_map_clear
|
- dma_buf_map_memcpy_to
+ iosys_map_memcpy_to
|
- dma_buf_map_incr
+ iosys_map_incr
)
@@
@@
- #include <linux/dma-buf-map.h>
+ #include <linux/iosys-map.h>
Then some files had their includes adjusted and some comments were
update to remove mentions to dma-buf-map.
Since this is not specific to dma-buf anymore, move the documentation to
the "Bus-Independent Device Accesses" section.
v2:
- Squash patches
v3:
- Fix wrong removal of dma-buf.h from MAINTAINERS
- Move documentation from dma-buf.rst to device-io.rst
v4:
- Change documentation title and level
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
First backmerge into drm-misc-next. Required for more helpers backmerged,
and to pull in 5.17 (rc2).
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[airlied: add two missing Kconfig]
drm-misc-next for v5.18:
UAPI Changes:
- Fix invalid IN_FORMATS blob when plane->format_mod_supported is NULL.
Cross-subsystem Changes:
- Assorted dt bindings updates.
- Fix vga16fb vga checking on x86.
- Fix extra semicolon in rwsem.h's _down_write_nest_lock.
- Assorted small fixes to agp and fbdev drivers.
- Fix oops in creating a udmabuf with 0 pages.
- Hot-unplug firmware fb devices on forced removal
- Reqquest memory region in simplefb and simpledrm, and don't make the ioresource as busy.
Core Changes:
- Mock a drm_plane in drm-plane-helper selftest.
- Assorted bug fixes to device logging, dbi.
- Use DP helper for sink count in mst.
- Assorted documentation fixes.
- Assorted small fixes.
- Move DP headers to drm/dp, and add a drm dp helper module.
- Move the buddy allocator from i915 to common drm.
- Add simple pci and platform module init macros to remove a lot of boilerplate from some drivers.
- Support microsoft extension for HMDs and specialized monitors.
- Improve edid parser's deep color handling.
- Add type 7 timing support to edid parser.
- Add a weak backpointer to the ttm_bo from ttm_resource
- Add 3 eDP panels.
Driver Changes:
- Add support for HDMI and JZ4780 to ingenic.
- Add support for higher DP/eDP bitrates to nouveau.
- Assorted driver fixes to tilcdc, vmwgfx, sn65dsi83, meson, stm, panfrost, v3d, gma500, vc4, virtio, mgag200, ast, radeon, amdgpu, nouveau, various bridge drivers.
- Convert and revert exynos dsi support to bridge driver.
- Add vcc supply regulator support for sn65dsi83.
- More conversion of bridge/chipone-icn6211 to atomic.
- Remove conflicting fb's from stm, and add support for new hw version.
- Add device link in parade-ps8640 to fix suspend/resume.
- Update Boe-tv110c9m init sequence.
- Add wide screen support to AST2600.
- Fix omapdrm implicit dma_buf fencing.
- Add support for multiple overlay planes to vkms.
- Convert bridge/anx7625 to atomic, add HDCP support,
add eld support for audio, and fix HPD.
- Add driver for ChromeOS privacy screen.
- Handover display from firmware to vc4 more gracefully, and support nomodeset.
- Add flexible and ycbcr pixel formats to stm/ltdc.
- Convert exynos mipi dsi to atomic.
- Add initial dual core group GPUs support to panfrost.
- No longer add exclusive fence in amdgpu as shared fence.
- Add CSC and full range supoprt to vc4.
- Shutdown the display on system shutdown and unbind.
- Add Multi-Inno Technology MI0700S4T-6 simple panel.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/456a23c6-7324-7543-0c45-751f30ef83f7@linux.intel.com
According to disable Documentation/admin-guide/kernel-parameters.txt, this
parameter can be used to disable kernel modesetting.
DRM drivers will not perform display-mode changes or accelerated rendering
and only the system framebuffer will be available if it was set-up.
But only a few DRM drivers currently check for nomodeset, make this driver
to also support the command line parameter.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217003752.3946210-30-javierm@redhat.com
System suspend uses pm_runtime_force_suspend(), which cheekily bypasses
the runpm reference counts. This doesn't actually work so well when the
GPU is active. So add a reasonable delay waiting for the GPU to become
idle.
Alternatively we could just return -EBUSY in this case, but that has the
disadvantage of causing system suspend to fail.
v2: s/ret/remaining [sboyd], and switch to using active_submits count
to ensure we aren't racing with submit cleanup (and devfreq idle
work getting scheduled, etc)
v3: fix inverted logic
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220108180913.814448-2-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>