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

[Daniel Baluta]

On Thu, Dec 4, 2025 at 2:29 PM Iuliana Prodan (OSS)
<iuliana.prodan at oss.nxp.com> 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>

Reviewed-by: Daniel Baluta <daniel.baluta at nxp.com>