linux-kernel - Re: System can not go into suspend when remoteproc is probed on AM62X

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Message-ID: <20250725233203.btxntw74cxktetv3@hiagonb>
Date: Fri, 25 Jul 2025 20:32:03 -0300
From: Hiago De Franco <hiagofranco@...il.com>
To: Andrew Davis <afd@...com>
Cc: linux-remoteproc@...r.kernel.org,
	Bjorn Andersson <andersson@...nel.org>,
	Mathieu Poirier <mathieu.poirier@...aro.org>,
	Suman Anna <s-anna@...com>, linux-kernel@...r.kernel.org,
	Hiago De Franco <hiago.franco@...adex.com>
Subject: Re: System can not go into suspend when remoteproc is probed on AM62X

Hi Andrew,

On Fri, Jul 25, 2025 at 02:29:22PM -0500, Andrew Davis wrote:
> So the issue then looks to be this message we send here when we setup
> the mailbox[0]. This mailbox setup is done during probe() for the K3
> rproc drivers now (mailbox setup used to be done during
> rproc_{start,attach}() before [1]). Moving mailbox setup to probe
> is correct, but we should have factored out the test message sending
> code out of mailbox setup so it could have been left in
> rproc_{start,attach}(). That way we only send this message if the
> core is going to be started, no sense in sending that message if
> we are not even going to run the core..
> 
> Fix might be as simple as [2] (not tested, if this works feel free
> to send as a fix)

Nice, thank you for the help and explanation. I will check if it works
and let you know.

Thanks!
Hiago

> 
> Andrew
> 
> [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/remoteproc/ti_k3_common.c#n176
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f3f11cfe890733373ddbb1ce8991ccd4ee5e79e1
> [2]
> 
> diff --git a/drivers/remoteproc/ti_k3_common.c b/drivers/remoteproc/ti_k3_common.c
> index a70d4879a8bea..657a200fa9040 100644
> --- a/drivers/remoteproc/ti_k3_common.c
> +++ b/drivers/remoteproc/ti_k3_common.c
> @@ -198,6 +198,22 @@ int k3_rproc_reset(struct k3_rproc *kproc)
>  }
>  EXPORT_SYMBOL_GPL(k3_rproc_reset);
> +static int k3_rproc_ping(struct k3_rproc *kproc)
> +{
> +       /*
> +        * Ping the remote processor, this is only for sanity-sake for now;
> +        * there is no functional effect whatsoever.
> +        *
> +        * Note that the reply will _not_ arrive immediately: this message
> +        * will wait in the mailbox fifo until the remote processor is booted.
> +        */
> +       int ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
> +       if (ret < 0)
> +               dev_err(kproc->dev, "mbox_send_message failed (%pe)\n", ERR_PTR(ret));
> +
> +       return ret;
> +}
> +
>  /* Release the remote processor from reset */
>  int k3_rproc_release(struct k3_rproc *kproc)
>  {
> @@ -221,6 +237,8 @@ int k3_rproc_release(struct k3_rproc *kproc)
>         if (ret)
>                 dev_err(dev, "module-reset deassert failed (%pe)\n", ERR_PTR(ret));
> +       k3_rproc_ping(kproc);
> +
>         return ret;
>  }
>  EXPORT_SYMBOL_GPL(k3_rproc_release);
> @@ -243,20 +261,6 @@ int k3_rproc_request_mbox(struct rproc *rproc)
>                 return dev_err_probe(dev, PTR_ERR(kproc->mbox),
>                                      "mbox_request_channel failed\n");
> -       /*
> -        * Ping the remote processor, this is only for sanity-sake for now;
> -        * there is no functional effect whatsoever.
> -        *
> -        * Note that the reply will _not_ arrive immediately: this message
> -        * will wait in the mailbox fifo until the remote processor is booted.
> -        */
> -       ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
> -       if (ret < 0) {
> -               dev_err(dev, "mbox_send_message failed (%pe)\n", ERR_PTR(ret));
> -               mbox_free_channel(kproc->mbox);
> -               return ret;
> -       }
> -
>         return 0;
>  }
>  EXPORT_SYMBOL_GPL(k3_rproc_request_mbox);
> @@ -397,7 +401,12 @@ EXPORT_SYMBOL_GPL(k3_rproc_stop);
>   * remote core. This callback is invoked only in IPC-only mode and exists
>   * because rproc_validate() checks for its existence.
>   */
> -int k3_rproc_attach(struct rproc *rproc) { return 0; }
> +int k3_rproc_attach(struct rproc *rproc)
> +{
> +       k3_rproc_ping(rproc->priv);
> +
> +       return 0;
> +}
>  EXPORT_SYMBOL_GPL(k3_rproc_attach);
>  /*
>