Re: [PATCH 3/3] remoteproc: imx_rproc: add power mode check for remote core attachment

[Peng Fan <peng.fan@oss.nxp.com>]

On Mon, May 05, 2025 at 12:48:49PM -0300, Hiago De Franco wrote:
>From: Hiago De Franco <hiago.franco@toradex.com>
>
>When the remote core is started before Linux boots (e.g., by the
>bootloader), the driver currently is not able to attach because it only
>checks for cores running in different partitions. If the core was kicked
>by the bootloader, it is in the same partition as Linux and it is
>already up and running.
>
>This adds power mode verification through the SCU interface, enabling
>the driver to detect when the remote core is already running and
>properly attach to it.
>
>Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
>Suggested-by: Peng Fan <peng.fan@oss.nxp.com>
>---
> drivers/remoteproc/imx_rproc.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
>diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
>index 627e57a88db2..86541d9d8640 100644
>--- a/drivers/remoteproc/imx_rproc.c
>+++ b/drivers/remoteproc/imx_rproc.c
>@@ -8,6 +8,7 @@
> #include <linux/clk.h>
> #include <linux/err.h>
> #include <linux/firmware/imx/sci.h>
>+#include <linux/firmware/imx/svc/misc.h>

Drop this line.

> #include <linux/interrupt.h>
> #include <linux/kernel.h>
> #include <linux/mailbox_client.h>
>@@ -906,6 +907,21 @@ static int imx_rproc_attach_pd(struct imx_rproc *priv)
> 	return ret < 0 ? ret : 0;
> }
> 
>+static bool imx_rproc_is_on(struct device *dev, struct imx_sc_ipc *ipc,
>+			    u32 resource)
>+{
>+	int ret;
>+
>+	ret = imx_sc_pm_get_resource_power_mode(ipc, resource);
>+	if (ret < 0) {
>+		dev_err(dev, "failed to get power resource %d mode, ret %d\n",
>+			resource, ret);
>+		return false;
>+	}
>+
>+	return ret == IMX_SC_PM_PW_MODE_ON;
>+}
>+
> static int imx_rproc_detect_mode(struct imx_rproc *priv)
> {
> 	struct regmap_config config = { .name = "imx-rproc" };
>@@ -949,6 +965,13 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv)
> 			if (of_property_read_u32(dev->of_node, "fsl,entry-address", &priv->entry))
> 				return -EINVAL;
> 
>+			/*
>+			 * If remote core is already running (e.g. kicked by
>+			 * the bootloader), attach to it.
>+			 */
>+			if (imx_rproc_is_on(dev, priv->ipc_handle, priv->rsrc_id))

I prefer "xyz == IMX_SC_PM_PW_MODE_ON"
But anyway, up to you. I not have strong opinion on this.

Regards,
Peng

>+				priv->rproc->state = RPROC_DETACHED;
>+
> 			return imx_rproc_attach_pd(priv);
> 		}
> 
>-- 
>2.39.5
>