Explicit management of the GPU's core stacks is only necessary in the
case of a broken integration with the PDC. Since there are no known
platforms which have such a broken integration let's remove the explicit
control from the driver since this apparently causes problems on other
platforms and will have a small performance penality.
The out of tree mali_kbase driver contains this text regarding
controlling the core stack (CONFIGMALI_CORESTACK):
Enabling this feature on supported GPUs will let the driver powering
on/off the GPU core stack independently without involving the Power
Domain Controller. This should only be enabled on platforms which
integration of the PDC to the Mali GPU is known to be problematic.
This feature is currently only supported on t-Six and t-HEx GPUs.
If unsure, say N.
Signed-off-by: Steven Price <steven.price@arm.com>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200109133104.11661-1-steven.price@arm.com
Entity currently keeps a copy of run_queue list and modify it in
drm_sched_entity_set_priority(). Entities shouldn't modify run_queue
list. Use drm_gpu_scheduler list instead of drm_sched_rq list
in drm_sched_entity struct. In this way we can select a runqueue based
on entity/ctx's priority for a drm scheduler.
Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm-misc-next for v5.6:
UAPI Changes:
- Add support for DMA-BUF HEAPS.
Cross-subsystem Changes:
- mipi dsi definition updates, pulled into drm-intel as well.
- Add lockdep annotations for dma_resv vs mmap_sem and fs_reclaim.
- Remove support for dma-buf kmap/kunmap.
- Constify fb_ops in all fbdev drivers, including drm drivers and drm-core, and media as well.
Core Changes:
- Small cleanups to ttm.
- Fix SCDC definition.
- Assorted cleanups to core.
- Add todo to remove load/unload hooks, and use generic fbdev emulation.
- Assorted documentation updates.
- Use blocking ww lock in ttm fault handler.
- Remove drm_fb_helper_fbdev_setup/teardown.
- Warning fixes with W=1 for atomic.
- Use drm_debug_enabled() instead of drm_debug flag testing in various drivers.
- Fallback to nontiled mode in fbdev emulation when not all tiles are present. (Later on reverted)
- Various kconfig indentation fixes in core and drivers.
- Fix freeing transactions in dp-mst correctly.
- Sean Paul is steping down as core maintainer. :-(
- Add lockdep annotations for atomic locks vs dma-resv.
- Prevent use-after-free for a bad job in drm_scheduler.
- Fill out all block sizes in the P01x and P210 definitions.
- Avoid division by zero in drm/rect, and fix bounds.
- Add drm/rect selftests.
- Add aspect ratio and alternate clocks for HDMI 4k modes.
- Add todo for drm_framebuffer_funcs and fb_create cleanup.
- Drop DRM_AUTH for prime import/export ioctls.
- Clear DP-MST payload id tables downstream when initializating.
- Fix for DSC throughput definition.
- Add extra FEC definitions.
- Fix fake offset in drm_gem_object_funs.mmap.
- Stop using encoder->bridge in core directly
- Handle bridge chaining slightly better.
- Add backlight support to drm/panel, and use it in many panel drivers.
- Increase max number of y420 modes from 128 to 256, as preparation to add the new modes.
Driver Changes:
- Small fixes all over.
- Fix documentation in vkms.
- Fix mmap_sem vs dma_resv in nouveau.
- Small cleanup in komeda.
- Add page flip support in gma500 for psb/cdv.
- Add ddc symlink in the connector sysfs directory for many drivers.
- Add support for analogic an6345, and fix small bugs in it.
- Add atomic modesetting support to ast.
- Fix radeon fault handler VMA race.
- Switch udl to use generic shmem helpers.
- Unconditional vblank handling for mcde.
- Miscellaneous fixes to mcde.
- Tweak debug output from komeda using debugfs.
- Add gamma and color transform support to komeda for DOU-IPS.
- Add support for sony acx424AKP panel.
- Various small cleanups to gma500.
- Use generic fbdev emulation in udl, and replace udl_framebuffer with generic implementation.
- Add support for Logic PD Type 28 panel.
- Use drm_panel_* wrapper functions in exynos/tegra/msm.
- Add devicetree bindings for generic DSI panels.
- Don't include drm_pci.h directly in many drivers.
- Add support for begin/end_cpu_access in udmabuf.
- Stop using drm_get_pci_dev in gma500 and mga200.
- Fixes to UDL damage handling, and use dma_buf_begin/end_cpu_access.
- Add devfreq thermal support to panfrost.
- Fix hotplug with daisy chained monitors by removing VCPI when disabling topology manager.
- meson: Add support for OSD1 plane AFBC commit.
- Stop displaying garbage when toggling ast primary plane on/off.
- More cleanups and fixes to UDL.
- Add D32 suport to komeda.
- Remove globle copy of drm_dev in gma500.
- Add support for Boe Himax8279d MIPI-DSI LCD panel.
- Add support for ingenic JZ4770 panel.
- Small null pointer deference fix in ingenic.
- Remove support for the special tfp420 driver, as there is a generic way to do it.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ba73535a-9334-5302-2e1f-5208bd7390bd@linux.intel.com
Currently when setting a frequency in panfrost_devfreq_target the
returned frequency is the actual frequency that the clock driver reports
(the return of clk_get_rate()). However, where the provided OPPs don't
precisely match the frequencies that the clock actually achieves devfreq
will then complain (repeatedly):
devfreq devfreq0: Couldn't update frequency transition information.
To avoid this change panfrost_devfreq_target() to fetch the opp using
devfreq_recommened_opp() and not actually query the clock for the
frequency.
A similar problem exists with panfrost_devfreq_get_cur_freq(), but in
this case because the function is optional we can just remove it and
devfreq will fall back to using the previously set frequency.
Fixes: 221bc77914 ("drm/panfrost: Use generic code for devfreq")
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191118173002.32015-1-steven.price@arm.com
We have the i915 security fixes to backmerge, but first
let's clear the decks for other drivers to avoid a bigger
mess.
Signed-off-by: Dave Airlie <airlied@redhat.com>
It seems that killing an application while faults are occurring
(particularly with a GPU in FPGA at a whopping 40MHz) can lead to
handling a lingering page fault after all the address space contexts
have already been freed. In this situation, the LRU list is empty so
addr_to_drm_mm_node() ends up dereferencing the list head as if it were
a struct panfrost_mmu entry; this leaves "mmu->as" actually pointing at
the pfdev->alloc_mask bitmap, which is also empty, and given that the
fault has a high likelihood of being in AS0, hilarity ensues.
Sadly, the cleanest solution seems to involve another goto. Oh well, at
least it's robust...
Fixes: 65e51e30d8 ("drm/panfrost: Prevent race when handling page fault")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/9a0b09e6b5851f0d4428b72dd6b8b4c0d0ef4206.1572293305.git.robin.murphy@arm.com
We get these warnings when build kernel W=1:
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:35:6: warning: no previous prototype for ‘panfrost_perfcnt_clean_cache_done’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:40:6: warning: no previous prototype for ‘panfrost_perfcnt_sample_done’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:190:5: warning: no previous prototype for ‘panfrost_ioctl_perfcnt_enable’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:218:5: warning: no previous prototype for ‘panfrost_ioctl_perfcnt_dump’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:250:6: warning: no previous prototype for ‘panfrost_perfcnt_close’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:264:5: warning: no previous prototype for ‘panfrost_perfcnt_init’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_perfcnt.c:320:6: warning: no previous prototype for ‘panfrost_perfcnt_fini’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_mmu.c:227:6: warning: no previous prototype for ‘panfrost_mmu_flush_range’ [-Wmissing-prototypes]
drivers/gpu/drm/panfrost/panfrost_mmu.c:435:5: warning: no previous prototype for ‘panfrost_mmu_map_fault_addr’ [-Wmissing-prototypes]
For file panfrost_mmu.c, make functions static to fix this.
For file panfrost_perfcnt.c, include header file can fix this.
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: stable@vger.kernel.org
[robh: fixup function parameter alignment]
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1571967015-42854-1-git-send-email-wang.yi59@zte.com.cn
Parroting Daniel's backmerge justification from
2e79e22e09:
Thierry needs fd70c7755b ("drm/bridge: tc358767: fix max_tu_symbol
value") to be able to merge his dp_link patch series.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Thierry needs fd70c7755b ("drm/bridge: tc358767: fix max_tu_symbol
value") to be able to merge his dp_link patch series.
Some adjacent changes conflicts, plus some clashes in i915 due to
cherry-picking and git trying to be helpful and leaving both versions
in.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Panfrost uses multiple schedulers (one for each slot, so 2 in reality),
and on a timeout has to stop all the schedulers to safely perform a
reset. However more than one scheduler can trigger a timeout at the same
time. This race condition results in jobs being freed while they are
still in use.
When stopping other slots use cancel_delayed_work_sync() to ensure that
any timeout started for that slot has completed. Also use
mutex_trylock() to obtain reset_lock. This means that only one thread
attempts the reset, the other threads will simply complete without doing
anything (the first thread will wait for this in the call to
cancel_delayed_work_sync()).
While we're here and since the function is already dependent on
sched_job not being NULL, let's remove the unnecessary checks.
Fixes: aa20236784 ("drm/panfrost: Prevent concurrent resets")
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191009094456.9704-1-steven.price@arm.com
Panfrost uses multiple schedulers (one for each slot, so 2 in reality),
and on a timeout has to stop all the schedulers to safely perform a
reset. However more than one scheduler can trigger a timeout at the same
time. This race condition results in jobs being freed while they are
still in use.
When stopping other slots use cancel_delayed_work_sync() to ensure that
any timeout started for that slot has completed. Also use
mutex_trylock() to obtain reset_lock. This means that only one thread
attempts the reset, the other threads will simply complete without doing
anything (the first thread will wait for this in the call to
cancel_delayed_work_sync()).
While we're here and since the function is already dependent on
sched_job not being NULL, let's remove the unnecessary checks.
Fixes: aa20236784 ("drm/panfrost: Prevent concurrent resets")
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191009094456.9704-1-steven.price@arm.com
We haven't done any backmerge for a while due to the merge window, and it
starts to become an issue for komeda. Let's bring 5.4-rc1 in.
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Pull drm fixes from Dave Airlie:
"Fixes built up over the past 1.5 weeks or so, it's two weeks of
amdgpu, some core cleanups and some panfrost fixes. I also finally
figured out why my desktop was slow to do a bunch of stuff (someone
gave it an IPv6 address which can't reach anything!).
core:
- Some cleanups and fixes in the self-refresh helpers
- Some cleanups and fixes in the atomic helpers
amdgpu:
- Fix a 64 bit divide
- Prevent a memory leak in a failure case in dc
- Load proper gfx firmware on navi14 variants
- Add more navi12 and navi14 PCI ids
- Misc fixes for renoir
- Fix bandwidth issues with multiple displays on vega20
- Support for Dali
- Fix a possible oops with KFD on hawaii
- Fix for backlight level after resume on some APUs
- Other misc fixes
panfrost:
- Multiple panfrost fixes for regulator support and page fault
handling"
* tag 'drm-next-2019-09-27' of git://anongit.freedesktop.org/drm/drm: (34 commits)
drm/amd/display: prevent memory leak
drm/amdgpu/gfx10: add support for wks firmware loading
drm/amdgpu/display: include slab.h in dcn21_resource.c
drm/amdgpu/display: fix 64 bit divide
drm/panfrost: Prevent race when handling page fault
drm/panfrost: Remove NULL checks for regulator
drm/panfrost: Fix regulator_get_optional() misuse
drm: Measure Self Refresh Entry/Exit times to avoid thrashing
drm: Fix kerneldoc and remove unused struct member in self_refresh helper
drm/atomic: Rename crtc_state->pageflip_flags to async_flip
drm/atomic: Reject FLIP_ASYNC unconditionally
drm/atomic: Take the atomic toys away from X
drm/amdgpu: flag navi12 and 14 as experimental for 5.4
drm/kms: Duct-tape for mode object lifetime checks
drm/amdgpu: add navi12 pci id
drm/amdgpu: add navi14 PCI ID for work station SKU
drm/amdkfd: Swap trap temporary registers in gfx10 trap handler
drm/amd/powerplay: implement sysfs for getting dpm clock
drm/amd/display: Restore backlight brightness after system resume
drm/amd/display: Implement voltage limitation for dali
...
Pull drm updates from Dave Airlie:
"This is the main pull request for 5.4-rc1 merge window. I don't think
there is anything outstanding so next week should just be fixes, but
we'll see if I missed anything. I landed some fixes earlier in the
week but got delayed writing summary and sending it out, due to a mix
of sick kid and jetlag!
There are some fixes pending, but I'd rather get the main merge out of
the way instead of delaying it longer.
It's also pretty large in commit count and new amd header file size.
The largest thing is four new amdgpu products (navi12/14, arcturus and
renoir APU support).
Otherwise it's pretty much lots of work across the board, i915 has
started landing tigerlake support, lots of icelake fixes and lots of
locking reworking for future gpu support, lots of header file rework
(drmP.h is nearly gone), some old legacy hacks (DRM_WAIT_ON) have been
put into the places they are needed.
uapi:
- content protection type property for HDCP
core:
- rework include dependencies
- lots of drmP.h removals
- link rate calculation robustness fix
- make fb helper map only when required
- add connector->DDC adapter link
- DRM_WAIT_ON removed
- drop DRM_AUTH usage from drivers
dma-buf:
- reservation object fence helper
dma-fence:
- shrink dma_fence struct
- merge signal functions
- store timestamps in dma_fence
- selftests
ttm:
- embed drm_get_object struct into ttm_buffer_object
- release_notify callback
bridges:
- sii902x - audio graph card support
- tc358767 - aux data handling rework
- ti-snd64dsi86 - debugfs support, DSI mode flags support
panels:
- Support for GiantPlus GPM940B0, Sharp LQ070Y3DG3B, Ortustech
COM37H3M, Novatek NT39016, Sharp LS020B1DD01D, Raydium RM67191, Boe
Himax8279d, Sharp LD-D5116Z01B
- TI nspire, NEC NL8048HL11, LG Philips LB035Q02, Sharp LS037V7DW01,
Sony ACX565AKM, Toppoly TD028TTEC1 Toppoly TD043MTEA1
i915:
- Initial tigerlake platform support
- Locking simplification work, general all over refactoring.
- Selftests
- HDCP debug info improvements
- DSI properties
- Icelake display PLL fixes, colorspace fixes, bandwidth fixes, DSI
suspend/resume
- GuC fixes
- Perf fixes
- ElkhartLake enablement
- DP MST fixes
- GVT - command parser enhancements
amdgpu:
- add wipe memory on release flag for buffer creation
- Navi12/14 support (may be marked experimental)
- Arcturus support
- Renoir APU support
- mclk DPM for Navi
- DC display fixes
- Raven scatter/gather support
- RAS support for GFX
- Navi12 + Arcturus power features
- GPU reset for Picasso
- smu11 i2c controller support
amdkfd:
- navi12/14 support
- Arcturus support
radeon:
- kexec fix
nouveau:
- improved display color management
- detect lack of GPU power cables
vmwgfx:
- evicition priority support
- remove unused security feature
msm:
- msm8998 display support
- better async commit support for cursor updates
etnaviv:
- per-process address space support
- performance counter fixes
- softpin support
mcde:
- DCS transfers fix
exynos:
- drmP.h cleanup
lima:
- reduce logging
kirin:
- misc clenaups
komeda:
- dual-link support
- DT memory regions
hisilicon:
- misc fixes
imx:
- IPUv3 image converter fixes
- 32-bit RGB V4L2 pixel format support
ingenic:
- more support for panel related cases
mgag200:
- cursor support fix
panfrost:
- export GPU features register to userspace
- gpu heap allocations
- per-fd address space support
pl111:
- CLD pads wiring support removed from DT
rockchip:
- rework to use DRM PSR helpers
- fix bug in VOP_WIN_GET macro
- DSI DT binding rework
sun4i:
- improve support for color encoding and range
- DDC enabled GPIO
tinydrm:
- rework SPI support
- improve MIPI-DBI support
- moved to drm/tiny
vkms:
- rework CRC tracking
dw-hdmi:
- get_eld and i2s improvements
gm12u320:
- misc fixes
meson:
- global code cleanup
- vpu feature detect
omap:
- alpha/pixel blend mode properties
rcar-du:
- misc fixes"
* tag 'drm-next-2019-09-18' of git://anongit.freedesktop.org/drm/drm: (2112 commits)
drm/nouveau/bar/gm20b: Avoid BAR1 teardown during init
drm/nouveau: Fix ordering between TTM and GEM release
drm/nouveau/prime: Extend DMA reservation object lock
drm/nouveau: Fix fallout from reservation object rework
drm/nouveau/kms/nv50-: Don't create MSTMs for eDP connectors
drm/i915: Use NOEVICT for first pass on attemping to pin a GGTT mmap
drm/i915: to make vgpu ppgtt notificaiton as atomic operation
drm/i915: Flush the existing fence before GGTT read/write
drm/i915: Hold irq-off for the entire fake lock period
drm/i915/gvt: update RING_START reg of vGPU when the context is submitted to i915
drm/i915/gvt: update vgpu workload head pointer correctly
drm/mcde: Fix DSI transfers
drm/msm: Use the correct dma_sync calls harder
drm/msm: remove unlikely() from WARN_ON() conditions
drm/msm/dsi: Fix return value check for clk_get_parent
drm/msm: add atomic traces
drm/msm/dpu: async commit support
drm/msm: async commit support
drm/msm: split power control from prepare/complete_commit
drm/msm: add kms->flush_commit()
...
When handling a GPU page fault addr_to_drm_mm_node() is used to
translate the GPU address to a buffer object. However it is possible for
the buffer object to be freed after the function has returned resulting
in a use-after-free of the BO.
Change addr_to_drm_mm_node to return the panfrost_gem_object with an
extra reference on it, preventing the BO from being freed until after
the page fault has been handled.
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190913160310.50444-1-steven.price@arm.com
The panfrost driver requests a supply using regulator_get_optional()
but both the name of the supply and the usage pattern suggest that it is
being used for the main power for the device and is not at all optional
for the device for function, there is no meaningful handling for absent
supplies. Such regulators should use the vanilla regulator_get()
interface, it will ensure that even if a supply is not described in the
system integration one will be provided in software.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904123032.23263-1-broonie@kernel.org
Currently, page tables are freed without disabling the address space first.
This probably is fine as we'll switch to new page tables when the address
space is allocated again and runtime PM suspend will reset the GPU
clearing the registers. However, it's better to clean up after ourselves.
There is also a problem that we could be accessing the h/w in
tlb_inv_context() when suspended.
Rework the disable code to make sure we flush caches/TLBs and disable the
address space before freeing the page tables if we are not suspended. As
the tlb_inv_context() hook is only called when freeing the page tables and
we do a flush before disabling the AS, lets remove the flush from
tlb_inv_context and avoid any runtime PM issues.
Fixes: 7282f7645d ("drm/panfrost: Implement per FD address spaces")
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190826223317.28509-8-robh@kernel.org
There's a few issues with the runtime PM initialization.
The documentation states pm_runtime_set_active() should be called before
pm_runtime_enable(). The pm_runtime_put_autosuspend() could suspend the GPU
before panfrost_perfcnt_init() is called which touches the h/w. The
autosuspend delay keeps things from breaking. There's no need explicitly
power off the GPU only to wake back up with pm_runtime_get_sync(). Just
delaying pm_runtime_enable to the end of probe is sufficient.
Lets move all the runtime PM calls into the probe() function so they are
all in one place and are done after all initialization.
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Steven Price <steven.price@arm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190826223317.28509-2-robh@kernel.org
While newer kbase include only the numbers of errata, older kbase
releases included one-line descriptions for each errata, which is useful
for those working on the driver. Import these descriptions. Most are
from kbase verbatim; a few I edited for clarity.
v2: Wrote a description for the workaround of an issue whose cause is
still unknown (Stephen). Errata which pertain to newer models
unsupported by the mainline driver, for which Arm has not yet released
errata information, have been removed from the issue list as the kernel
need not concern itself with these.
v3: Readded errata not yet handled, adding descriptions based on the
workarounds in the latest kbase release.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190823155149.7272-1-alyssa.rosenzweig@collabora.com
If there is no regulator defined for the GPU then still control the
frequency using the supplied clock.
Some boards have clock control but no (direct) control of the regulator.
For example the HiKey960 uses a mailbox protocol to a MCU to control
frequencies and doesn't directly control the voltage. This patch allows
frequency control of the GPU on this system.
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190816093107.30518-1-steven.price@arm.com
