[PATCH v2] remoteproc: uclass: Modify uc_pdata->name to use combination of device name and device's parent name

[MD Danish Anwar]

uc_pdata->name is populated from device tree property "remoteproc-name".
For those devcices that don't set "remoteproc-name", uc_pdata->name
falls back to dev->name.

If two devices have same name, this will result into uc_pdata->name not
being unique and rproc_init() will fail.

Fix this by using combination of dev->name and dev->parent->name instead
of using just the dev->name to populate uc_pdata->name.

Signed-off-by: MD Danish Anwar <danishanwar at ti.com>
---
Cc: Andrew Davis <afd at ti.com>

Failure Example:
In k3-am64-main.dtsi, both pru0_0 [1] and pru1_0 [2] will have
dev->name as "pru at 34000" although their parent name is different.

pru0_0 has dev->name as "pru at 34000" and parent name as "icssg at 30000000"
pru1_0 has dev->name as "pru at 34000" and parent name as "icssg at 30080000"

rproc_init() fails for pru1_0 as the the uc_pdata->name becomes same as the pru0_0.
More details on this issue can be found here [3]. It was suggested to use a
different combination if `dev->name` is not unique by Andrew Davis <afd at ti.com> [4]

Failure Logs:
	rproc_pre_probe: 'pru at 34000': using fdt
	rproc_pre_probe: 'pru at 34000': using fdt
	rproc_pre_probe: pru at 34000 duplicate name 'pru at 34000'
	_rproc_probe_dev: pru at 34000: Failed to initialize - -22
	rproc_boot: rproc_init() failed: -22

To fix it, this commit uses combination of dev and dev's parent name.

After this commit,
pru0_0 uc->pdata->name = "pru at 34000-icssg@30000000"
pru1_0 uc->pdata->name = "pru at 34000-icssg@30080000"

Both the names are unique, thus rproc_init() succeeds.

Changes since v1:
*) Instead of hardcoding rproc_name_size to 256, changed it to be equal to
   strlen(dev->name) + strlen(dev->parent->name) + 2 as suggested by
   Roger Quadros <rogerq at kernel.org>
 *) Added check for malloc failure as suggested by Roger Quadros <rogerq at kernel.org>

[v1] https://lore.kernel.org/all/20240719085908.3564171-1-danishanwar@ti.com/
[1] https://elixir.bootlin.com/u-boot/v2024.07-rc3/source/dts/upstream/src/arm64/ti/k3-am64-main.dtsi#L1276
[2] https://elixir.bootlin.com/u-boot/v2024.07-rc3/source/dts/upstream/src/arm64/ti/k3-am64-main.dtsi#L1417
[3] https://lore.kernel.org/all/5cda289f-1d14-41f6-84e3-ff1d1034be13@ti.com/
[4] https://lore.kernel.org/all/e48f5818-182c-47ab-b384-379659830d38@ti.com/

 drivers/remoteproc/rproc-uclass.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/remoteproc/rproc-uclass.c b/drivers/remoteproc/rproc-uclass.c
index e64354dd52..3233ff8041 100644
--- a/drivers/remoteproc/rproc-uclass.c
+++ b/drivers/remoteproc/rproc-uclass.c
@@ -158,9 +158,19 @@ static int rproc_pre_probe(struct udevice *dev)
 		uc_pdata->driver_plat_data = pdata->driver_plat_data;
 	}
 
-	/* Else try using device Name */
-	if (!uc_pdata->name)
-		uc_pdata->name = dev->name;
+	/* Else try using a combination of device Name and devices's parent's name */
+	if (!uc_pdata->name) {
+		/* 2 in the rproc_name_size indicates 1 for null and one for '-' */
+		int rproc_name_size = strlen(dev->name) + strlen(dev->parent->name) + 2;
+		char *buf;
+
+		buf = malloc(rproc_name_size);
+		if (!buf)
+			return -ENOMEM;
+
+		snprintf(buf, rproc_name_size, "%s-%s", dev->name, dev->parent->name);
+		uc_pdata->name = buf;
+	}
 	if (!uc_pdata->name) {
 		debug("Unnamed device!");
 		return -EINVAL;

base-commit: 6f4c31c2b658358628b5b0fa801f55c7477c7585
-- 
2.34.1