When the manager device is pm_runtime resumed, we see a series of
spurious wakes and attempts to resume the same device:
soundwire_intel.link.0: intel_resume_runtime: start
soundwire_intel.link.0: intel_link_power_up: powering up all links
soundwire_intel.link.0: intel_link_power_up: first link up, programming SYNCPRD
soundwire_intel.link.0: intel_shim_wake: WAKEEN disabled for link 0
soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume start
soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume done
soundwire_intel.link.0: intel_shim_wake: WAKEEN disabled for link 0
soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume start
soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume done
This sequence does not break anything but is totally unnecessary.
Currently the wakes are only disabled after the peripheral generates a
wake, e.g. for jack detection.
If the resume is initiated by the host drivers as a result of
userspace actions (play/record typically), we need to disable wake
detection as well. Doing so prevents the spurious wakes and calls to
pm_request_resume().
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220420023241.14335-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
commit e38f9ff63e ("ACPI: scan: Do not add device IDs from _CID if _HID is not valid")
exposes a race condition on a TGL RVP device leading to a timeout.
The detailed analysis shows the RT711 codec driver scheduling a jack
detection workqueue while attaching during a spurious pm_runtime
resume, and the work function happens to be scheduled after the
manager device is suspended.
The direct link between this ACPI patch and a spurious pm_runtime
resume is not obvious; the most likely explanation is that a change in
the ACPI device linked list management modifies the order in which the
pm_runtime device status is checked and exposes a race condition that
was probably present for a very long time, but was not identified.
We already have a check in the .prepare stage, where we will resume to
full power from specific clock-stop modes. In all other cases, we
don't need to resume to full power by default. Adding the
SMART_SUSPEND flag prevents the spurious resume from happening.
BugLink: https://github.com/thesofproject/linux/issues/3459
Fixes: 029bfd1cd5 ("soundwire: intel: conditionally exit clock stop mode on system suspend")
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220420023241.14335-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull sound updates from Takashi Iwai:
"It's a relatively calm development cycle, but still lots of updates in
the driver side like Intel SOF. Below are some highlights:
ALSA / ASoC core:
- A new kselftest for ALSA control API
- PCM NO_REWINDS support
- Potential race fixes around control removals
- Unify x86 SG-buffer memory allocation code
- Cleanups and race fixes for ASoC DPCM locking
ASoC:
- Refinements and cleanups around the delay() APIs
- Wider use of dev_err_probe().
- Continuing cleanups and improvements to the SOF code
- Support for pin switches in simple-card derived cards
- Support for AMD Renoir ACP, Asahi Kasei Microdevices AKM4375, Intel
systems using NAU8825 and MAX98390, Mediatek MT8915, nVidia Tegra20
S/PDIF, Qualcomm systems using ALC5682I-VS and Texas Instruments
TLV320ADC3xxx
HD-audio / USB-audio:
- Fix deadlock at HD-audio codec unbinding
- Fixes for Tegra194 HD-audio, new HDA support for CS35L41 codec
- Quirks for Lenovo and HP machines, Gigabyte mobo, Bose device
Misc:
- Fix virmidi drain behavior
Note that the merge of CS35L41 codec support is still half-baked, and
at least one ACPI change is missing. Although this won't hinder the
kernel build itself, we're going to catch up before RC1"
* tag 'sound-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (415 commits)
ALSA: hda: intel-dsp-config: reorder the config table
ALSA: hda: intel-dsp-config: add JasperLake support
ALSA: hda: cs35l41: fix double free on error in probe()
ALSA: hda: Fix dependencies of CS35L41 on SPI/I2C buses
ALSA: hda: Fix dependency on ASoC cs35l41 codec
ASoC: cs35l41: Add support for hibernate memory retention mode
ASoC: cs35l41: Update handling of test key registers
ALSA: intel_hdmi: Check for error num after setting mask
ASoC: wcd9335: Keep a RX port value for each SLIM RX mux
ASoC: amd: acp: acp-mach: Change default RT1019 amp dev id
ALSA: virmidi: Remove duplicated code
ALSA: seq: virmidi: Add a drain operation
ASoC: topology: Fix typo
ASoC: fsl_asrc: refine the check of available clock divider
ASoC: Intel: bytcr_rt5640: Add support for external GPIO jack-detect
ASoC: Intel: bytcr_rt5640: Support retrieving the codec IRQ from the AMCR0F28 ACPI dev
ASoC: rt5640: Add support for boards with an external jack-detect GPIO
ASoC: rt5640: Allow snd_soc_component_set_jack() to override the codec IRQ
ASoC: rt5640: Change jack_work to a delayed_work
ASoC: rt5640: Fix possible NULL pointer deref on resume
...
The HDAudio ASoC support relies on the set_tdm_slots() helper to store
the HDaudio stream tag in the tx_mask. This only works because of the
pre-existing order in soc-pcm.c, where the hw_params() is handled for
codec_dais *before* cpu_dais. When the order is reversed, the
stream_tag is used as a mask in the codec fixup functions:
/* fixup params based on TDM slot masks */
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
codec_dai->tx_mask)
soc_pcm_codec_params_fixup(&codec_params,
codec_dai->tx_mask);
As a result of this confusion, the codec_params_fixup() ends-up
generating bad channel masks, depending on what stream_tag was
allocated.
We could add a flag to state that the tx_mask is really not a mask,
but it would be quite ugly to persist in overloading concepts.
Instead, this patch suggests a more generic get/set 'stream' API based
on the existing model for SoundWire. We can expand the concept to
store 'stream' opaque information that is specific to different DAI
types. In the case of HDAudio DAIs, we only need to store a stream tag
as an unsigned char pointer. The TDM rx_ and tx_masks should really
only be used to store masks.
Rename get_sdw_stream/set_sdw_stream callbacks and helpers as
get_stream/set_stream. No functionality change beyond the rename.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20211224021034.26635-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch provides both a simplification of the suspend flows and a
better balanced operation during suspend/resume transition, as part of
the transition of Sound Open Firmware (SOF) to dynamic pipelines: the
DSP resources are only enabled when required instead of enabled on
startup.
The exiting code relies on a convoluted way of dealing with suspend
signals. Since there is no .suspend DAI callback, we used the
component .suspend and marked all the component DAI dmas as
'suspended'. The information was used in the .prepare stage to
differentiate resume operations from xrun handling, and only
reinitialize SHIM registers and DMA in the former case.
While this solution has been working reliably for about 2 years, there
is a much better solution consisting in trapping the TRIGGER_SUSPEND
in the .trigger DAI ops. The DMA is still marked in the same way for
the .prepare op to run, but in addition the callbacks sent to DSP
firmware are now balanced.
Normal operation:
hw_params -> intel_params_stream
hw_free -> intel_free_stream
suspend -> intel_free_stream
prepare -> intel_params_stream
This balanced operation was not required with existing SOF firmware
relying on static pipelines instantiated at every boot. With the
on-going transition to dynamic pipelines, it's however a requirement
to keep the use count for the DAI widget balanced across all
transitions.
The component suspend is not removed but instead modified to deal with
a corner case: when a substream is PAUSED, the ALSA core does not
throw the TRIGGER_SUSPEND. This is problematic since the refcount for
all pipelines and widgets is not balanced, leading to issues on
resume. The trigger callback keeps track of the 'paused' state with a
new flag, which is tested during the component suspend called later to
release the remaining DSP resources. These resources will be
re-enabled in the .prepare step.
The IPC used in the TRIGGER_SUSPEND to release DSP resources is not a
problem since the BE dailink is already marked as non-atomic.
Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20211224021034.26635-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull sound updates from Takashi Iwai:
"There are a few intensive changes in ALSA core side at this time that
helped with significant code reduction. Meanwhile we keep getting new
stuff, so the total size still grows...
Anyway, the below are some highlights in this development cycle.
ALSA core:
- New helpers to manage page allocations and card object with devres
- Refactoring for memory allocation with wc-pages
- A new PCM hardware flag SNDRV_PCM_INFO_EXPLICIT_SYNC for
controlling the explicit sync of the stream control; it'll be used
for ASoC SOF and non-coherent memory in future
ASoC:
- Lots of cleanups and improvements to the Intel drivers, including
some new systems support
- New support for AMD Vangoh, CUI CMM-4030D-261, Mediatek Mt8195,
Renesas RZ/G2L Mediatek Mt8195, RealTek RT101P, Renesas RZ/G2L,
Rockchip RK3568 S/PDIF
USB-audio:
- Re-organized the quirk handling and a new option quirk_flags
- Fix for a regression in 5.14 code change for JACK
- Quirks for Sony WALKMAN, Digidesign mbox
HD-audio:
- Enhanced support for CS8409 codec
- More consistent shutdown behavior with the runtime PM
- The model option can accept the PCI or codec SSID as an alias
- Quirks for ASUS ROG, HP Spectre x360
Others:
- Lots of code reduction in legacy drivers with devres helpers
- FireWire MOTU 896HD support"
* tag 'sound-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (421 commits)
ASoC: Revert PCM trigger changes
ALSA: usb-audio: Add lowlatency module option
ALSA: hda/cs8409: Initialize Codec only in init fixup.
ALSA: hda/cs8409: Ensure Type Detection is only run on startup when necessary
ALSA: usb-audio: Work around for XRUN with low latency playback
ALSA: pcm: fix divide error in snd_pcm_lib_ioctl
ASoC: soc-pcm: test refcount before triggering
ASoC: soc-pcm: protect BE dailink state changes in trigger
ASoC: wcd9335: Disable irq on slave ports in the remove function
ASoC: wcd9335: Fix a memory leak in the error handling path of the probe function
ASoC: wcd9335: Fix a double irq free in the remove function
ALSA: hda: Disable runtime resume at shutdown
ASoC: rockchip: i2s: Add support for frame inversion
ASoC: dt-bindings: rockchip: Add compatible strings for more SoCs
ASoC: rockchip: i2s: Add compatible for more SoCs
ASoC: rockchip: i2s: Make playback/capture optional
ASoC: rockchip: i2s: Fixup config for DAIFMT_DSP_A/B
ASoC: dt-bindings: rockchip: Document reset property for i2s
ASoC: rockchip: i2s: Fix regmap_ops hang
ASoC: rockchip: i2s: Improve dma data transfer efficiency
...
Intel stress tests reported issues with the clock stop mode,
specifically when trying to do a system suspend while the link is
already pm_runtime suspended.
In this case, we need to disable the shim wake, but when the PCI
parent device is also pm_runtime suspended the SHIM registers are not
accessible.
Since this is an invalid corner case, this patch suggests a pm_runtime
resume of the entire bus to full power (parent+child devices) before
the system suspend so that the shim wake can be disabled.
Unlike the suspend operation, the .prepare callbacks are propagated
from root device to leaf devices. By adding a .prepare callback at the
SoundWire link level, we can double-check the pm_runtime status of the
device as well as its parent PCI device. When the problematic
configuration is detected, the device is pm_runtime resumed - which by
construction also resume its parent.
An additional loop is added to resume all child devices. In theory we
only need to restart the link, but doing so will also cause the
physical devices to synchronize and re-initialize, while their Linux
devices remain pm_runtime suspended. It's simpler to make sure the
codec devices are fully resumed so that we don't have to deal with
zombie states.
This additional loop could have been avoided by adding a .prepare
callback in SoundWire codec drivers. Functionally this would have been
equivalent. The rationale for implementing a loop at the link level is
only to reduce the amount of code required to deal at the codec level
with an Intel corner case - in other words keep codec drivers
independent from Intel platform-specific programming sequences.
BugLink: https://github.com/thesofproject/linux/issues/2606
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210818024954.16873-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The SoundWire Linux devices are created purely based on information
provided by platform firmware (e.g. ACPI DSDT table). When the kernel
finds a matching driver for the device address (_ADR), the probe will
initialize required data structures and initialize pm ops.
When the SoundWire link is started at a later point, the physical
devices will synchronize on the SoundWire frames and report their
attachment status, thereby triggering the enumeration and
initialization of device registers.
This two-step solution was a conscious design decision to allow e.g. a
driver to use sideband mechanisms to turn power rails on. This can
also allow OEMs to describe multiple platforms with the same DSDT
table, the devices that are not physically present in hardware.
The drawback of this approach is a bit of confusion, with more devices
than are actually present in hardware. This results in 'ghost'
devices, for which the driver successfully probes, but that will not
generate any traffic on the bus. suspend-resume transitions are
handled by drivers, and skipped when the devices are not physically
present.
This patch provides a work-around for a second-level of confusion in
platform firmware: some platforms only use HDaudio links, but
nevertheless expose SoundWire 'ghost' devices. This results in error
messages in the Intel driver while trying to suspend/resume these
links. The simplest solution is to add a boolean status flag to skip
all suspend/resume/wake sequences if the link was never started.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The Cadence IP exposes a small number of self-clearing bits in
the MCP_CONTROL and MCP_CONFIG_UPDATE registers.
We currently do not check that those bits are indeed cleared,
e.g. during resume operations. That could lead to resuming peripheral
devices too early.
In addition, if we happen to read these registers, update one of the
fields and write the register back, we may be writing stale data that
might have been cleared in hardware. These sort of race conditions
could lead to e.g. doing a hw_reset twice or stopping a clock that
just restarted. There is no clear way of avoiding these potential race
conditions other than making sure that these registers fields are
cleared before any read-modify-write sequence. If we detect this sort
of errors, we only log them since there is no clear recovery
possible. The only way out is likely to restart the IP with a
suspend/resume cycle.
Note that the checks are performed before updating the registers, as
well as after the Intel 'sync go' sequence in multi-link mode. That
should cover both the start and end of suspend/resume hardware
configurations. The Multi-Master mode gates the configuration updates
until the 'sync go' signal is asserted, so we only check on init and
after the end of the 'sync go' sequence.
The duration of the usleep_range() was defined by the GSYNC frequency
used in multi-master mode. With a 4kHz frequency, any configuration
change might be deferred by up to 250us. Extending the range to
1000-1500us should guarantee that the configuration change is
completed without any significant impact on the overall resume
time.
Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Now that the auxiliary_bus exists, there's no reason to use platform
devices as children of a PCI device any longer.
This patch refactors the code by extending a basic auxiliary device
with Intel link-specific structures that need to be passed between
controller and link levels. This refactoring is much cleaner with no
need for cross-pointers between device and link structures.
Note that the auxiliary bus API has separate init and add steps, which
requires more attention in the error unwinding paths. The main loop
needs to deal with kfree() and auxiliary_device_uninit() for the
current iteration before jumping to the common label which releases
everything allocated in prior iterations.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210511052132.28150-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dev->power.runtime_error will be set to the return value of the runtime
suspend callback function, and runtime resume function will return
-EINVAL if dev->power.runtime_error is not 0.
Somehow the codec rarely doesn't return an ACK to the clock prepare
command. If we stop the runtime suspend process and return error, we
will not be able to resume again. Likewise, if the codec lost sync and
did not rejoin, the resume operation will also fail. As a result, the
SoundWire bus can not be used anymore.
This patch suggests to finish the runtime suspend process even if we fail
to stop sdw bus clock. In the case where we do a hardware reset, the codecs
will be reconfigured completely. In the case where we use the regular clock
stop, the codecs keep their state and worst case will fall off the bus and
reattach.
The only drawback is that the power consumption may be higher and
device-initiated interrupts may be lost, but at least audio function can
still work after resume.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210114030248.9005-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Without CONFIG_PM, there is another warning about an unused function:
drivers/soundwire/intel.c:530:12: error: 'intel_link_power_down' defined but not used [-Werror=unused-function]
After a previous fix, the driver already uses both an #ifdef and
a __maybe_unused annotation but still gets it wrong. Remove the
ifdef and instead use __maybe_unused consistently to avoid the
problem for good.
Fixes: f046b23340 ("soundwire: intel: fix intel_suspend/resume defined but not used warning")
Fixes: ebf878eddb ("soundwire: intel: add pm_runtime support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20201203230502.1480063-1-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This algorithm computes bus parameters like clock frequency, frame
shape and port transport parameters based on active stream(s) running
on the bus.
Developers can also implement their own .compute_params() callback for
specific resource management algorithm, and set if before calling
sdw_add_bus_master()
Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah. All hard-coded
values were removed from the initial contribution to use BIOS
information instead.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200908131520.5712-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When CONFIG_PM_SLEEP is not defined, GCC throws compilation warnings:
drivers/soundwire/intel.c:1799:12: warning: ‘intel_resume’ defined but not
used [-Wunused-function]
static int intel_resume(struct device *dev)
^~~~~~~~~~~~
drivers/soundwire/intel.c:1683:12: warning: ‘intel_suspend’ defined but not
used [-Wunused-function]
static int intel_suspend(struct device *dev)
^~~~~~~~~~~~~
Fix by using __maybe_unused macro.
Suggested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200824133234.28115-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When all the links are suspended, the HDaudio controller may suspend
and the power rails to the SoundWire IP may be disabled, requiring a
complete re-initialization/enumeration on resume. However, if one or
more Masters remained active, the HDaudio controller will remain active
and the power rails will remain enabled. As a result, during the link
resume step we can check if the context was preserved by verifying if
the clock was stopped, and avoid doing a complete bus reset and
re-enumeration.
Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-13-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The .prepare() callback is invoked for normal streaming, underflows or
during the system resume transition. In the latter case, the context
for the ALH PDIs is lost, and the DSP is not initialized properly
either, but the bus parameters don't need to be recomputed.
Conversely, when doing a regular .prepare() during an underflow, the
ALH/SHIM registers shall not be changed as the hardware cannot be
reprogrammed after the DMA started (hardware spec requirement).
This patch adds storage of PDI and hw_params in the DAI dma context,
and the difference between the types of .prepare() usages is handled
via a simple boolean, updated when suspending, and tested for in the
.prepare() case.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The system resume does the entire bus re-initialization and brings it
to full-power. If the device was pm_runtime suspended, there is no
need to run the pm_runtime resume sequence after the system runtime.
Follow the documentation from runtime_pm.rst, and conditionally
disable, set_active and re-enable the device on system resume.
Note that pm_runtime_suspended() is used instead of
pm_runtime_status_suspended() so that we can deal with the case where
pm_runtime is disabled.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
