Subject: Re: [PATCH 04/10] remoteproc: imx_rproc: make syscon optional

Hi Peng,

On Fri, Jul 24, 2020 at 04:08:07PM +0800, Peng Fan wrote:

quoted

Make syscon optional, since i.MX8QM/QXP/7ULP not have SRC to control

M4.

quoted

But currently i.MX8QM/QXP/7ULP not added, so still check regmap when
start/stop to avoid unhappy things.

On the i.MX8QM/QXP/7ULP processors, the remote processors are not
handled by the remoteproc cores, as implemented in this patch.  In such a
scenario how does the remoteproc core know the remote processor has
crashed and how does it recover from such a condition?

For 7ULP dual boot case, A7 is under control of M4, so if m4 crash, I suppose
A7 would not work properly.

For 8QM/QXP partition case, M4 is in a standalone partition, if M4 crash or
reboot, the system controller unit will restart M4 and notify Acore that M4
restart.

Thanks,
Peng.

Thanks,
Mathieu

quoted

Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/remoteproc/imx_rproc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/imx_rproc.c

b/drivers/remoteproc/imx_rproc.c index 82594a800a1b..4fad5c0b1c05
100644

--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c

@@ -162,6 +162,9 @@ static int imx_rproc_start(struct rproc *rproc)
 	struct device *dev = priv->dev;
 	int ret;

+	if (!priv->regmap)
+		return -EOPNOTSUPP;
+
 	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
 				 dcfg->src_mask, dcfg->src_start);
 	if (ret)

@@ -177,6 +180,9 @@ static int imx_rproc_stop(struct rproc *rproc)
 	struct device *dev = priv->dev;
 	int ret;

+	if (!priv->regmap)
+		return -EOPNOTSUPP;
+
 	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
 				 dcfg->src_mask, dcfg->src_stop);
 	if (ret)

@@ -325,9 +331,10 @@ static int imx_rproc_probe(struct platform_device

*pdev)

quoted

 	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
 	if (IS_ERR(regmap)) {
 		dev_err(dev, "failed to find syscon\n");
-		return PTR_ERR(regmap);
+		regmap = NULL;
+	} else {
+		regmap_attach_dev(dev, regmap, &config);
 	}
-	regmap_attach_dev(dev, regmap, &config);

 	/* set some other name then imx */
 	rproc = rproc_alloc(dev, "imx-rproc", &imx_rproc_ops,
--
2.16.4

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