Re: [PATCH 06/14] ASoC: Intel: avs: Coredump and recovery flow

[Cezary Rojewski <cezary.rojewski@intel.com>]

On 2022-04-26 11:53 PM, Pierre-Louis Bossart wrote:
> On 4/26/22 12:23, Cezary Rojewski wrote:
>> In rare occassions, under stress conditions or hardware malfunction, DSP
> 
> occasions


Ack.

>> firmware may fail. Software is notified about such situation with
>> EXCEPTION_CAUGHT notification. IPC timeout is also counted as critical
>> device failure. More often than not, driver can recover from such
>> situations by performing full reset: killing and restarting ADSP.
>>
>> Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
>> Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
>> ---
>>   sound/soc/intel/Kconfig        |  1 +
>>   sound/soc/intel/avs/avs.h      |  4 ++
>>   sound/soc/intel/avs/ipc.c      | 95 +++++++++++++++++++++++++++++++++-
>>   sound/soc/intel/avs/messages.h |  5 ++
>>   4 files changed, 103 insertions(+), 2 deletions(-)
>>
>> diff --git a/sound/soc/intel/Kconfig b/sound/soc/intel/Kconfig
>> index c364ddf22267..05ad6bdecfc5 100644
>> --- a/sound/soc/intel/Kconfig
>> +++ b/sound/soc/intel/Kconfig
>> @@ -218,6 +218,7 @@ config SND_SOC_INTEL_AVS
>>   	select SND_HDA_EXT_CORE
>>   	select SND_HDA_DSP_LOADER
>>   	select SND_INTEL_NHLT
>> +	select WANT_DEV_COREDUMP
>>   	help
>>   	  Enable support for Intel(R) cAVS 1.5 platforms with DSP
>>   	  capabilities. This includes Skylake, Kabylake, Amberlake and
>> diff --git a/sound/soc/intel/avs/avs.h b/sound/soc/intel/avs/avs.h
>> index e628f78d1864..02c2aa1bcd5c 100644
>> --- a/sound/soc/intel/avs/avs.h
>> +++ b/sound/soc/intel/avs/avs.h
>> @@ -42,6 +42,7 @@ struct avs_dsp_ops {
>>   	int (* const load_basefw)(struct avs_dev *, struct firmware *);
>>   	int (* const load_lib)(struct avs_dev *, struct firmware *, u32);
>>   	int (* const transfer_mods)(struct avs_dev *, bool, struct avs_module_entry *, u32);
>> +	int (* const coredump)(struct avs_dev *, union avs_notify_msg *);
>>   };
>>   
>>   #define avs_dsp_op(adev, op, ...) \
>> @@ -164,12 +165,15 @@ struct avs_ipc {
>>   	struct avs_ipc_msg rx;
>>   	u32 default_timeout_ms;
>>   	bool ready;
>> +	bool recovering;
>>   
>>   	bool rx_completed;
>>   	spinlock_t rx_lock;
>>   	struct mutex msg_mutex;
>>   	struct completion done_completion;
>>   	struct completion busy_completion;
>> +
>> +	struct work_struct recovery_work;
>>   };
>>   
>>   #define AVS_EIPC	EREMOTEIO
>> diff --git a/sound/soc/intel/avs/ipc.c b/sound/soc/intel/avs/ipc.c
>> index 68aaf01edbf2..84cb411c82fa 100644
>> --- a/sound/soc/intel/avs/ipc.c
>> +++ b/sound/soc/intel/avs/ipc.c
>> @@ -14,6 +14,87 @@
>>   
>>   #define AVS_IPC_TIMEOUT_MS	300
>>   
>> +static void avs_dsp_recovery(struct avs_dev *adev)
>> +{
>> +	struct avs_soc_component *acomp;
>> +	unsigned int core_mask;
>> +	int ret;
>> +
>> +	if (adev->ipc->recovering)
>> +		return;
>> +	adev->ipc->recovering = true;
> 
> don't you need some sort of lock to test/clear this flag?

Our stress tests do not confirm this. I'll not ignore this warning 
though, will recheck with my team next week.

>> +
>> +	mutex_lock(&adev->comp_list_mutex);
>> +	/* disconnect all running streams */
>> +	list_for_each_entry(acomp, &adev->comp_list, node) {
>> +		struct snd_soc_pcm_runtime *rtd;
>> +		struct snd_soc_card *card;
>> +
>> +		card = acomp->base.card;
>> +		if (!card)
>> +			continue;
>> +
>> +		for_each_card_rtds(card, rtd) {
>> +			struct snd_pcm *pcm;
>> +			int dir;
>> +
>> +			pcm = rtd->pcm;
>> +			if (!pcm || rtd->dai_link->no_pcm)
>> +				continue;
>> +
>> +			for_each_pcm_streams(dir) {
>> +				struct snd_pcm_substream *substream;
>> +
>> +				substream = pcm->streams[dir].substream;
>> +				if (!substream || !substream->runtime)
>> +					continue;
>> +
>> +				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
>> +			}
>> +		}
>> +	}
>> +	mutex_unlock(&adev->comp_list_mutex);
>> +
>> +	/* forcibly shutdown all cores */
>> +	core_mask = GENMASK(adev->hw_cfg.dsp_cores - 1, 0);
>> +	avs_dsp_core_disable(adev, core_mask);
>> +
>> +	/* attempt dsp reboot */
>> +	ret = avs_dsp_boot_firmware(adev, true);
>> +	if (ret < 0)
>> +		dev_err(adev->dev, "dsp reboot failed: %d\n", ret);
>> +
>> +	pm_runtime_mark_last_busy(adev->dev);
>> +	pm_runtime_enable(adev->dev);
>> +	pm_request_autosuspend(adev->dev);
> 
> there are zero users of this routine in the entire sound/ tree, can you clarify why this is needed or what you are trying to do?


Unsure which routine you question here. I'll assume it's 
pm_request_autosuspend().

pm_request_audiosuspend() is being used to queue suspend once recovery 
completes. Recovery takes time and during that time all communication 
attempts with DSP will yield -EPERM. PM is also blocked for the device 
with pm_runtime_disable(), performed before scheduling the recovery 
work. Once recovery completes we do not just unblock the PM as that 
would cause immediate suspend. Instead, we "refresh" the *last busy* 
status and queue the suspend operation.

>> +
>> +	adev->ipc->recovering = false;
>> +}