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

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Message-ID: <aR9WvVjvBhXoO3oh@p14s>
Date: Thu, 20 Nov 2025 10:58:21 -0700
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: Tanmay Shah <tanmay.shah@....com>
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 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

>  	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.

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
>