<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/soundwire/intel.c, branch linux-6.3.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>soundwire: intel: don't save hw_params for use in prepare</title>
<updated>2023-05-11T14:17:35+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2023-03-21T02:26:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4ddae1bef783a01dc099ec1dbeee0560bbe15f4a'/>
<id>4ddae1bef783a01dc099ec1dbeee0560bbe15f4a</id>
<content type='text'>
[ Upstream commit 0a0d1740bd8fd7dafb81fcb102fb5d0b83b1ce73 ]

The existing code copies the hw_params pointer and reuses it later in
.prepare, specifically to re-initialize the ALH DMA channel
information that's lost in suspend-resume cycles.

This is not needed, we can directly access the information from the
substream/rtd - as done for the HDAudio DAIs in
sound/soc/sof/intel/hda-dai.c

In addition, using the saved pointer causes the suspend-resume test
cases to fail on specific platforms, depending on which version of GCC
is used. Péter Ujfalusi and I have spent long hours to root-cause this
problem that was reported by the Intel CI first with 6.2-rc1 and again
v6.3-rc1. In the latter case we were lucky that the problem was 100%
reproducible on local test devices, and found out that adding a
dev_dbg() or adding a call to usleep_range() just before accessing the
saved pointer "fixed" the issue. With errors appearing just by
changing the compiler version or minor changes in the code generated,
clearly we have a memory management Heisenbug.

The root-cause seems to be that the hw_params pointer is not
persistent. The soc-pcm code allocates the hw_params structure on the
stack, and passes it to the BE dailink hw_params and DAIs
hw_params. Saving such a pointer and reusing it later during the
.prepare stage cannot possibly work reliably, it's broken-by-design
since v5.10. It's astonishing that the problem was not seen earlier.

This simple fix will have to be back-ported to -stable, due to changes
to avoid the use of the get/set_dmadata routines this patch will only
apply on kernels older than v6.1.

Fixes: a5a0239c27fe ("soundwire: intel: reinitialize IP+DSP in .prepare(), but only when resuming")
Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Ranjani Sridharan &lt;ranjani.sridharan@linux.intel.com&gt;
Reviewed-by: Péter Ujfalusi &lt;peter.ujfalusi@linux.intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230321022642.1426611-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0a0d1740bd8fd7dafb81fcb102fb5d0b83b1ce73 ]

The existing code copies the hw_params pointer and reuses it later in
.prepare, specifically to re-initialize the ALH DMA channel
information that's lost in suspend-resume cycles.

This is not needed, we can directly access the information from the
substream/rtd - as done for the HDAudio DAIs in
sound/soc/sof/intel/hda-dai.c

In addition, using the saved pointer causes the suspend-resume test
cases to fail on specific platforms, depending on which version of GCC
is used. Péter Ujfalusi and I have spent long hours to root-cause this
problem that was reported by the Intel CI first with 6.2-rc1 and again
v6.3-rc1. In the latter case we were lucky that the problem was 100%
reproducible on local test devices, and found out that adding a
dev_dbg() or adding a call to usleep_range() just before accessing the
saved pointer "fixed" the issue. With errors appearing just by
changing the compiler version or minor changes in the code generated,
clearly we have a memory management Heisenbug.

The root-cause seems to be that the hw_params pointer is not
persistent. The soc-pcm code allocates the hw_params structure on the
stack, and passes it to the BE dailink hw_params and DAIs
hw_params. Saving such a pointer and reusing it later during the
.prepare stage cannot possibly work reliably, it's broken-by-design
since v5.10. It's astonishing that the problem was not seen earlier.

This simple fix will have to be back-ported to -stable, due to changes
to avoid the use of the get/set_dmadata routines this patch will only
apply on kernels older than v6.1.

Fixes: a5a0239c27fe ("soundwire: intel: reinitialize IP+DSP in .prepare(), but only when resuming")
Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Ranjani Sridharan &lt;ranjani.sridharan@linux.intel.com&gt;
Reviewed-by: Péter Ujfalusi &lt;peter.ujfalusi@linux.intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230321022642.1426611-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: remove DAI startup/shutdown</title>
<updated>2023-01-09T16:03:49+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-12-15T08:54:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5c2f4c9cfc79028079f0691899a93843827a00b7'/>
<id>5c2f4c9cfc79028079f0691899a93843827a00b7</id>
<content type='text'>
The only thing these DAI startup/shutdown callbacks do is play with
pm_runtime reference counts.

This is not wrong, but it's not necessary at all. At the ASoC core level,
only the component matters for pm_runtime. The ASoC core already calls
pm_runtime_get_sync() in snd_soc_pcm_component_pm_runtime_get(),
before the DAI startup callback is invoked.

None of the SoundWire codec drivers rely on pm_runtime helpers in
their DAI startup/shutdown either. This adds to the evidence that only
the component, or more precisely the device specified when registering
a component, should deal with pm_runtime transitions.

Beyond the code cleanup, this move prepares for the addition of link
power management in the auxiliary device startup/resume/suspend
callbacks. The DAI callbacks can by-design assume that the device is
already pm_runtime active.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Ranjani Sridharan &lt;ranjani.sridharan@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Reviewed-by: Péter Ujfalusi &lt;peter.ujfalusi@linux.intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221215085436.2001568-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The only thing these DAI startup/shutdown callbacks do is play with
pm_runtime reference counts.

This is not wrong, but it's not necessary at all. At the ASoC core level,
only the component matters for pm_runtime. The ASoC core already calls
pm_runtime_get_sync() in snd_soc_pcm_component_pm_runtime_get(),
before the DAI startup callback is invoked.

None of the SoundWire codec drivers rely on pm_runtime helpers in
their DAI startup/shutdown either. This adds to the evidence that only
the component, or more precisely the device specified when registering
a component, should deal with pm_runtime transitions.

Beyond the code cleanup, this move prepares for the addition of link
power management in the auxiliary device startup/resume/suspend
callbacks. The DAI callbacks can by-design assume that the device is
already pm_runtime active.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Ranjani Sridharan &lt;ranjani.sridharan@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Reviewed-by: Péter Ujfalusi &lt;peter.ujfalusi@linux.intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221215085436.2001568-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: split auxdevice to different file</title>
<updated>2022-11-23T14:41:49+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7cbf00bd4142cd88ac7ecbc4ea7b917a220cb721'/>
<id>7cbf00bd4142cd88ac7ecbc4ea7b917a220cb721</id>
<content type='text'>
The auxdevice layer is completely generic, it should be split from
intel.c which is only geared to the 'cnl' hw_ops now.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The auxdevice layer is completely generic, it should be split from
intel.c which is only geared to the 'cnl' hw_ops now.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: add in-band wake callbacks in hw_ops</title>
<updated>2022-11-23T14:41:49+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36e3b385f35a33a10b792ec46350dd87d79e84dd'/>
<id>36e3b385f35a33a10b792ec46350dd87d79e84dd</id>
<content type='text'>
No functionality change, only add indirection for in-band wake
management helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change, only add indirection for in-band wake
management helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: add link power management callbacks in hw_ops</title>
<updated>2022-11-23T14:41:49+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=49c9ff45991a5a62e040c8b43c89a9ab38a0a91f'/>
<id>49c9ff45991a5a62e040c8b43c89a9ab38a0a91f</id>
<content type='text'>
No functionality change, only add indirection for link power
management helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change, only add indirection for link power
management helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: add bus management callbacks in hw_ops</title>
<updated>2022-11-23T14:41:48+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3db0c5a6a2832c7b4b40676299e4bbbe1a96bc8b'/>
<id>3db0c5a6a2832c7b4b40676299e4bbbe1a96bc8b</id>
<content type='text'>
No functionality change, only add indirection for bus management
helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change, only add indirection for bus management
helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: add register_dai callback in hw_ops</title>
<updated>2022-11-23T14:41:48+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b6234bcc6589a0719ec91d810114c0b556a5b88b'/>
<id>b6234bcc6589a0719ec91d810114c0b556a5b88b</id>
<content type='text'>
No functionality change, only add indirection for DAI registration
helper.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change, only add indirection for DAI registration
helper.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: add debugfs callbacks in hw_ops</title>
<updated>2022-11-23T14:41:48+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fb2dc6a0a5f885233d632b1e92be9c0be977b0dc'/>
<id>fb2dc6a0a5f885233d632b1e92be9c0be977b0dc</id>
<content type='text'>
No functionality change, only add indirection for debugfs helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change, only add indirection for debugfs helpers.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soundwire: intel: start using hw_ops</title>
<updated>2022-11-23T14:41:48+00:00</updated>
<author>
<name>Pierre-Louis Bossart</name>
<email>pierre-louis.bossart@linux.intel.com</email>
</author>
<published>2022-11-11T01:31:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3ad31f33982497dbc7a66a9d3013b1ac6985dfe'/>
<id>b3ad31f33982497dbc7a66a9d3013b1ac6985dfe</id>
<content type='text'>
Before introducing new hardware with completely different register
spaces and programming sequences, we need to abstract some of the
existing routines in hw_ops that will be platform-specific. For now we
only use the 'cnl' ops - after the first Intel platform with SoundWire
capabilities.

Rather than one big intrusive patch, hw_ops are introduced in this
patch so show the dependencies between drivers. Follow-up patches will
introduce callbacks for debugfs, power and bus management.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Before introducing new hardware with completely different register
spaces and programming sequences, we need to abstract some of the
existing routines in hw_ops that will be platform-specific. For now we
only use the 'cnl' ops - after the first Intel platform with SoundWire
capabilities.

Rather than one big intrusive patch, hw_ops are introduced in this
patch so show the dependencies between drivers. Follow-up patches will
introduce callbacks for debugfs, power and bus management.

Signed-off-by: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Reviewed-by: Rander Wang &lt;rander.wang@intel.com&gt;
Signed-off-by: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20221111013135.38289-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'fixes' into next</title>
<updated>2022-11-23T14:21:09+00:00</updated>
<author>
<name>Vinod Koul</name>
<email>vkoul@kernel.org</email>
</author>
<published>2022-11-23T14:21:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ca1c131ccf6e09f4976aeca035f12529c9a7d8a9'/>
<id>ca1c131ccf6e09f4976aeca035f12529c9a7d8a9</id>
<content type='text'>
Merge fixes into next as Intel driver has a dependency
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge fixes into next as Intel driver has a dependency
</pre>
</div>
</content>
</entry>
</feed>
