[PATCH v2 1/3] remoteproc: imx_dsp_rproc: Skip RP_MBOX_SUSPEND_SYSTEM when mailbox TX channel is uninitialized

[Mathieu Poirier]

On Thu, Dec 04, 2025 at 02:28:23PM +0200, Iuliana Prodan (OSS) wrote:
> From: Iuliana Prodan <iuliana.prodan at nxp.com>
> 
> Firmwares that do not use mailbox communication (e.g., the hello_world
> sample) leave priv->tx_ch as NULL. The current suspend logic
> unconditionally sends RP_MBOX_SUSPEND_SYSTEM, which is invalid without
> an initialized TX channel.
> 
> Detect the no_mailboxes case early and skip sending the suspend
> message. Instead, proceed directly to the runtime PM suspend path,
> which is the correct behavior for firmwares that cannot respond to
> mailbox requests.
> 
> Signed-off-by: Iuliana Prodan <iuliana.prodan at nxp.com>
> ---
> Changes since v1:
> - Wrapped commit message to 75 characters
> - Changed dev_err to dev_dbg since this case is normal behavior
> ---
>  drivers/remoteproc/imx_dsp_rproc.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>

I have applied all 3 patches in this set.  Next time, please consider adding a
cover letter.

Thanks,
Mathieu
 
> diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
> index 5130a35214c9..f51deaacc700 100644
> --- a/drivers/remoteproc/imx_dsp_rproc.c
> +++ b/drivers/remoteproc/imx_dsp_rproc.c
> @@ -1242,6 +1242,15 @@ static int imx_dsp_suspend(struct device *dev)
>  	if (rproc->state != RPROC_RUNNING)
>  		goto out;
>  
> +	/*
> +	 * No channel available for sending messages;
> +	 * indicates no mailboxes present, so trigger PM runtime suspend
> +	 */
> +	if (!priv->tx_ch) {
> +		dev_dbg(dev, "No initialized mbox tx channel, suspend directly.\n");
> +		goto out;
> +	}
> +
>  	reinit_completion(&priv->pm_comp);
>  
>  	/* Tell DSP that suspend is happening */
> -- 
> 2.25.1
>