remoteproc: xlnx: Check remote core state

The remote state is set to RPROC_DETACHED if the resource table is found
in the memory. However, this can be wrong if the remote is not started,
but firmware is still loaded in the memory. Use PM_GET_NODE_STATUS call
to the firmware to request the state of the RPU node. If the RPU is
actually out of reset and running, only then move the remote state to
RPROC_DETACHED, otherwise keep the remote state to RPROC_OFFLINE.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Fixes: bca4b02ef92e ("remoteproc: xlnx: Add attach detach support")
Reviewed-by: Beleswar Padhi <b-padhi@ti.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20260428221855.313752-1-tanmay.shah@amd.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

1 files changed, 36 insertions, 10 deletions

diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
index 50a9974f3202..45a62cb98072 100644
--- a/drivers/remoteproc/xlnx_r5_remoteproc.c
+++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
@@ -948,16 +948,6 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
 		goto free_rproc;
 	}
 
-	/*
-	 * If firmware is already available in the memory then move rproc state
-	 * to DETACHED. Firmware can be preloaded via debugger or by any other
-	 * agent (processors) in the system.
-	 * If firmware isn't available in the memory and resource table isn't
-	 * found, then rproc state remains OFFLINE.
-	 */
-	if (!zynqmp_r5_get_rsc_table_va(r5_core))
-		r5_rproc->state = RPROC_DETACHED;
-
 	r5_core->rproc = r5_rproc;
 	return r5_core;
 
@@ -1210,6 +1200,7 @@ static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster,
 {
 	struct device *dev = cluster->dev;
 	struct zynqmp_r5_core *r5_core;
+	u32 req, usage, status;
 	int ret = -EINVAL, i;
 
 	r5_core = cluster->r5_cores[0];
@@ -1255,6 +1246,41 @@ static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster,
 		ret = zynqmp_r5_get_sram_banks(r5_core);
 		if (ret)
 			return ret;
+
+		/*
+		 * It is possible that firmware is loaded into the memory, but
+		 * RPU (remote) is not running. In such case, RPU state will be
+		 * moved to RPROC_DETACHED wrongfully. To avoid it first make
+		 * sure RPU is power-on and out of reset before parsing for the
+		 * resource table.
+		 */
+		ret = zynqmp_pm_get_rpu_node_status(r5_core->pm_domain_id,
+						    &status, &req, &usage);
+		if (ret) {
+			dev_warn(r5_core->dev,
+				 "failed to get rpu node status, err %d\n", ret);
+			continue;
+		}
+
+		/*
+		 * If RPU state is power on and out of reset i.e. running, then
+		 * assign RPROC_DETACHED state. If the RPU is not out of reset
+		 * then do not attempt to attach to the remote processor.
+		 */
+		if (status == PM_NODE_RUNNING) {
+			/*
+			 * Not all the firmware that is running on the remote
+			 * core is expected to have the resource table. The
+			 * firmware might not use RPMsg at all, and in that case
+			 * resource table becomes irrelevant. However, we still
+			 * need to make sure that running core is not reported
+			 * as offline. so do not decide remote core state based
+			 * on the resource table availability
+			 */
+			if (zynqmp_r5_get_rsc_table_va(r5_core))
+				dev_dbg(r5_core->dev, "rsc tbl not found\n");
+			r5_core->rproc->state = RPROC_DETACHED;
+		}
 	}
 
 	return 0;