diff options
Diffstat (limited to '0105-soundwire_intel-use_pm_runtime_resume_on_component_probe.patch')
| -rw-r--r-- | 0105-soundwire_intel-use_pm_runtime_resume_on_component_probe.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/0105-soundwire_intel-use_pm_runtime_resume_on_component_probe.patch b/0105-soundwire_intel-use_pm_runtime_resume_on_component_probe.patch new file mode 100644 index 000000000000..d096bc6268aa --- /dev/null +++ b/0105-soundwire_intel-use_pm_runtime_resume_on_component_probe.patch @@ -0,0 +1,79 @@ +From 928a0c25a874a13d69d58ef68fede866259b039b Mon Sep 17 00:00:00 2001 +From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> +Date: Tue, 21 Jun 2022 17:56:40 -0500 +Subject: [PATCH] soundwire: intel: use pm_runtime_resume() on component probe +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +During the card registration, transactions on the SoundWire bus can be +initiated. If the ALSA card is registered after the bus suspends, +timeouts can be seen while reading/writing codec registers. This is +extremely easy to reproduce in driver bind/unbind tests. + +In an initial experiment, the ASoC soc-component.c code was modified +to initiate a pm_runtime resume on a component probe. The results +showed this was too invasive. Instead this patch suggests resuming the +SoundWire component only. + +Because of the parent-child hierarchy enforced by the pm_runtime +framework, it can be argued that the codec component probe should be +enough to resume all necessary devices, and indeed the same resume +will be applied to SoundWire codecs used on Intel platforms. + +Calling pm_runtime_resume() on both the Intel and codec sides has the +benefit of resuming the bus without assuming any order during the card +registration. The first component on a dailink to be probed will +resume the bus. In addition, if a codec driver did not implement this +transition, the Intel component would still resume the bus and avoid +timeouts on card registration. + +BugLink: https://github.com/thesofproject/linux/issues/3651 +Reviewed-by: Rander Wang <rander.wang@intel.com> +Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> +Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com> +Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com> +Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> +Link: https://lore.kernel.org/r/20220621225641.221170-4-pierre-louis.bossart@linux.intel.com +Signed-off-by: Vinod Koul <vkoul@kernel.org> +--- + drivers/soundwire/intel.c | 18 ++++++++++++++++++ + 1 file changed, 18 insertions(+) + +diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c +index 505c5ef061e3f5..95ce292994ccb6 100644 +--- a/drivers/soundwire/intel.c ++++ b/drivers/soundwire/intel.c +@@ -1043,6 +1043,23 @@ static int intel_trigger(struct snd_pcm_substream *substream, int cmd, struct sn + return ret; + } + ++static int intel_component_probe(struct snd_soc_component *component) ++{ ++ int ret; ++ ++ /* ++ * make sure the device is pm_runtime_active before initiating ++ * bus transactions during the card registration. ++ * We use pm_runtime_resume() here, without taking a reference ++ * and releasing it immediately. ++ */ ++ ret = pm_runtime_resume(component->dev); ++ if (ret < 0 && ret != -EACCES) ++ return ret; ++ ++ return 0; ++} ++ + static int intel_component_dais_suspend(struct snd_soc_component *component) + { + struct snd_soc_dai *dai; +@@ -1098,6 +1115,7 @@ static const struct snd_soc_dai_ops intel_pcm_dai_ops = { + + static const struct snd_soc_component_driver dai_component = { + .name = "soundwire", ++ .probe = intel_component_probe, + .suspend = intel_component_dais_suspend + }; + + |