On Mon, Dec 15, 2025 at 03:26:05PM +0800, Jacky Bai wrote:
> On i.MX7ULP platform, certain drivers that depend on rpmsg may need
> to send an rpmsg request and receive an acknowledgment from the
> remote core during the late_suspend stage. In the current imx_rproc
> implementation, rx_callback defers message handling to a workqueue.
> However, this deferred work may not execute before the system enters
> the noirq_suspend stage. When that happens, pending mailbox IRQs
> will cause the suspend sequence to abort.
>
> To address this, handle incoming messages synchronously within
> rx_callback when running on i.MX7ULP. This ensures the message is
> processed immediately, allows the mailbox IRQ to be cleared in time,
> and prevents suspend failures.
>
> Signed-off-by: Jacky Bai <[email protected]>
> ---
> drivers/remoteproc/imx_rproc.c | 49
> ++++++++++++++++++++++++++++++++++++++++--
> drivers/remoteproc/imx_rproc.h | 1 +
> 2 files changed, 48 insertions(+), 2 deletions(-)
>
...
>
> - queue_work(priv->workqueue, &priv->rproc_work);
> + if (priv->use_sync_rx)
> + idr_for_each(&rproc->notifyids, imx_rproc_notified_idr_cb,
> rproc);
> + else
> + queue_work(priv->workqueue, &priv->rproc_work);
> }
>
> static int imx_rproc_xtr_mbox_init(struct rproc *rproc, bool tx_block)
> @@ -1009,6 +1015,38 @@ static int imx_rproc_sys_off_handler(struct
> sys_off_data *data)
> return NOTIFY_DONE;
> }
>
> +static int imx_rproc_pm_notify(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + int ret;
> + struct imx_rproc *priv = container_of(nb, struct imx_rproc, pm_nb);
struct imx_rproc *priv = container_of(nb, struct imx_rproc, pm_nb);
int ret;
> +
> + imx_rproc_free_mbox(priv->rproc);
> +
> + switch (action) {
> + case PM_SUSPEND_PREPARE:
> + ret = imx_rproc_xtr_mbox_init(priv->rproc, false);
Any risk condition if on going message during free() and _init()?
> + if (ret) {
> + dev_err(&priv->rproc->dev, "Failed to request
> non-blocking mbox\n");
> + return NOTIFY_BAD;
> + }
> + priv->use_sync_rx = true;
> + break;
> + case PM_POST_SUSPEND:
> + ret = imx_rproc_xtr_mbox_init(priv->rproc, true);
> + if (ret) {
> + dev_err(&priv->rproc->dev, "Failed to request blocking
> mbox\n");
> + return NOTIFY_BAD;
> + }
> + priv->use_sync_rx = false;
> + break;
> + default:
> + break;
imx_rproc_free_mbox() here? if other notify comming, mbox is free() as
expected?
Frank
> + }
> +
> + return NOTIFY_OK;
> +}
> +
> static void imx_rproc_destroy_workqueue(void *data)
> {
> struct workqueue_struct *workqueue = data;
> @@ -1103,6 +1141,13 @@ static int imx_rproc_probe(struct platform_device
> *pdev)
> return dev_err_probe(dev, ret, "register restart
> handler failure\n");
> }
>
> + if (dcfg->flags & IMX_RPROC_NEED_PM_SYNC) {
> + priv->pm_nb.notifier_call = imx_rproc_pm_notify;
> + ret = register_pm_notifier(&priv->pm_nb);
> + if (ret)
> + return dev_err_probe(dev, ret, "register pm notifier
> failure\n");
> + }
> +
> pm_runtime_enable(dev);
> ret = pm_runtime_resume_and_get(dev);
> if (ret)
> @@ -1202,7 +1247,7 @@ static const struct imx_rproc_dcfg
> imx_rproc_cfg_imx8ulp = {
> static const struct imx_rproc_dcfg imx_rproc_cfg_imx7ulp = {
> .att = imx_rproc_att_imx7ulp,
> .att_size = ARRAY_SIZE(imx_rproc_att_imx7ulp),
> - .flags = IMX_RPROC_NEED_SYSTEM_OFF,
> + .flags = IMX_RPROC_NEED_SYSTEM_OFF | IMX_RPROC_NEED_PM_SYNC,
> };
>
> static const struct imx_rproc_dcfg imx_rproc_cfg_imx7d = {
> diff --git a/drivers/remoteproc/imx_rproc.h b/drivers/remoteproc/imx_rproc.h
> index
> 1b2d9f4d6d19dcdc215be97f7e2ab3488281916a..0e3e460cef4ed9340fb4977183e03143c84764af
> 100644
> --- a/drivers/remoteproc/imx_rproc.h
> +++ b/drivers/remoteproc/imx_rproc.h
> @@ -18,6 +18,7 @@ struct imx_rproc_att {
> /* dcfg flags */
> #define IMX_RPROC_NEED_SYSTEM_OFF BIT(0)
> #define IMX_RPROC_NEED_CLKS BIT(1)
> +#define IMX_RPROC_NEED_PM_SYNC BIT(2)
>
> struct imx_rproc_plat_ops {
> int (*start)(struct rproc *rproc);
>
> ---
> base-commit: 5ce74bc1b7cb2732b22f9c93082545bc655d6547
> change-id: 20251211-imx7ulp_rproc-57999329239b
>
> Best regards,
> --
> Jacky Bai <[email protected]>
>
