linux-kernel - Re: [PATCH v2 2/3] remoteproc: core: full attach detach during recovery

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Message-ID: <af34e73c-0e66-4150-ba2b-2cf616dd68d3@amd.com>
Date: Mon, 1 Dec 2025 17:05:50 -0600
From: Tanmay Shah <tanmay.shah@....com>
To: Mathieu Poirier <mathieu.poirier@...aro.org>
CC: <andersson@...nel.org>, <linux-remoteproc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/3] remoteproc: core: full attach detach during
 recovery



On 11/20/25 11:58 AM, Mathieu Poirier wrote:
> On Thu, Nov 13, 2025 at 07:44:03AM -0800, Tanmay Shah wrote:
>> Current attach on recovery mechanism loads the clean resource table
>> during recovery, but doesn't re-allocate the resources. RPMsg
>> communication will fail after recovery due to this. Fix this
>> incorrect behavior by doing the full detach and attach of remote
>> processor during the recovery. This will load the clean resource table
>> and re-allocate all the resources, which will set up correct vring
>> information in the resource table.
>>
>> Signed-off-by: Tanmay Shah <tanmay.shah@....com>
>> ---
>>
>> Changes in v2:
>>    - use rproc_boot instead of rproc_attach
>>    - move debug message early in the function
>>
>>   drivers/remoteproc/remoteproc_core.c | 26 +++++++++++++++-----------
>>   1 file changed, 15 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index aada2780b343..f65e8bc2d1e1 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -1777,11 +1777,11 @@ static int rproc_attach_recovery(struct rproc *rproc)
>>   {
>>   	int ret;
>>   
>> -	ret = __rproc_detach(rproc);
>> +	ret = rproc_detach(rproc);
>>   	if (ret)
>>   		return ret;
>>   
>> -	return __rproc_attach(rproc);
>> +	return rproc_boot(rproc);
>>   }
>>   
>>   static int rproc_boot_recovery(struct rproc *rproc)
>> @@ -1829,6 +1829,11 @@ int rproc_trigger_recovery(struct rproc *rproc)
>>   	struct device *dev = &rproc->dev;
>>   	int ret;
>>   
>> +	dev_err(dev, "recovering %s\n", rproc->name);
>> +
>> +	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
>> +		return rproc_attach_recovery(rproc);
>> +
> 
> Humm... I find this a little messy.  Taking [1] as an example, I suggest moving
> the "unlock_mutex" block to line 1846 and add mutex calls to
> rproc_boot_recovery().  That way both rproc_attach_recovery() and
> rproc_boot_recovery() are called the same way.
> 
> [1] https://elixir.bootlin.com/linux/v6.17.8/source/drivers/remoteproc/remoteproc_core.c#L1832
> 

Sounds good. I will have to test it but I don't see problem with the 
suggestion made.

>>   	ret = mutex_lock_interruptible(&rproc->lock);
>>   	if (ret)
>>   		return ret;
>> @@ -1837,12 +1842,7 @@ int rproc_trigger_recovery(struct rproc *rproc)
>>   	if (rproc->state != RPROC_CRASHED)
>>   		goto unlock_mutex;
>>   
>> -	dev_err(dev, "recovering %s\n", rproc->name);
>> -
>> -	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
>> -		ret = rproc_attach_recovery(rproc);
>> -	else
>> -		ret = rproc_boot_recovery(rproc);
>> +	ret = rproc_boot_recovery(rproc);
>>   
>>   unlock_mutex:
>>   	mutex_unlock(&rproc->lock);
>> @@ -1860,6 +1860,7 @@ static void rproc_crash_handler_work(struct work_struct *work)
>>   {
>>   	struct rproc *rproc = container_of(work, struct rproc, crash_handler);
>>   	struct device *dev = &rproc->dev;
>> +	int ret;
>>   
>>   	dev_dbg(dev, "enter %s\n", __func__);
>>   
>> @@ -1883,8 +1884,11 @@ static void rproc_crash_handler_work(struct work_struct *work)
>>   
>>   	mutex_unlock(&rproc->lock);
>>   
>> -	if (!rproc->recovery_disabled)
>> -		rproc_trigger_recovery(rproc);
>> +	if (!rproc->recovery_disabled) {
>> +		ret = rproc_trigger_recovery(rproc);
>> +		if (ret)
>> +			dev_warn(dev, "rproc recovery failed, err %d\n", ret);
> 
> I would prefer a patch on its own for this one.
> 

Ack.

> I'm running out of time for today, I'll review patch 3/3 tomorrow.
> 
> Thanks,
> Mathieu
> 
>> +	}
>>   
>>   out:
>>   	pm_relax(rproc->dev.parent);
>> @@ -2057,7 +2061,7 @@ int rproc_detach(struct rproc *rproc)
>>   		return ret;
>>   	}
>>   
>> -	if (rproc->state != RPROC_ATTACHED) {
>> +	if (rproc->state != RPROC_ATTACHED && rproc->state != RPROC_CRASHED) {
>>   		ret = -EINVAL;
>>   		goto out;
>>   	}
>> -- 
>> 2.34.1
>>