On 12/15/2025 9:26 AM, 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(-)
diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index
3be8790c14a2ccc789dd40508ec274000ec09978..1127c56388fd94f296c80db5c01a5d431d669c4d
100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -22,6 +22,7 @@
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/remoteproc.h>
+#include <linux/suspend.h>
#include <linux/workqueue.h>
#include "imx_rproc.h"
@@ -111,11 +112,13 @@ struct imx_rproc {
void __iomem *rsc_table;
struct imx_sc_ipc *ipc_handle;
struct notifier_block rproc_nb;
+ struct notifier_block pm_nb;
u32 rproc_pt; /* partition id */
u32 rsrc_id; /* resource id */
u32 entry; /* cpu start address */
u32 core_index;
struct dev_pm_domain_list *pd_list;
+ bool use_sync_rx;
};
static const struct imx_rproc_att imx_rproc_att_imx93[] = {
@@ -725,7 +728,10 @@ static void imx_rproc_rx_callback(struct mbox_client *cl,
void *msg)
struct rproc *rproc = dev_get_drvdata(cl->dev);
struct imx_rproc *priv = rproc->priv;
- 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);
+
+ imx_rproc_free_mbox(priv->rproc);
Here you free mailbox unconditinally.
+
+ switch (action) {
+ case PM_SUSPEND_PREPARE:
When switching to sync mode, any pending work in the workqueue should be
flushed to avoid processing messages twice.
+ ret = imx_rproc_xtr_mbox_init(priv->rproc, false);
+ 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;
+ }
If imx_rproc_xtr_mbox_init() fails in either case, the mailbox channels
remain freed but the function returns NOTIFY_BAD. The system may
continue with freed mailbox channels.
Only free the mailbox if re-initialization succeeds, or ensure proper
cleanup on failure.
+ priv->use_sync_rx = false;
+ break;
+ default:
+ break;
+ }
+
+ 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");
+ }
+
The PM notifier is registered in probe but never unregistered in remove
or error paths.
Thanks,
Iulia
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,
