On Wed, Aug 19, 2020 at 12:51:27AM +0000, Peng Fan wrote:

quoted

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.

In that case I assume the whole system gets rebooted, which puts the A7 in a
state where it can "attach" with the M4 again.

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.

And how does that notification work exactly?  Does rproc_report_crash() get
called somewhere in that process in order for the remoteproc core to attach to
the M4 again?

Many thanks for the help,
Mathieu

Thanks,
Peng.

quoted

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