[PATCH] firmware: arm_ffa: Treat missing FF-A feature on a platform as a probe miss

[Sudeep Holla]

When FF-A initialisation is driven from a platform device probe, systems
that do not implement FF-A can return -EOPNOTSUPP from the early transport
or version discovery paths. Driver core treats that as a matched probe
failure and prints:

  |  arm-ffa arm-ffa: probe with driver arm-ffa failed with error -95

That is noisy for a firmware interface that can be absent on otherwise
valid systems. Driver core already treats -ENODEV and -ENXIO as quiet
rejected matches, so translate only the early unsupported discovery cases
to -ENODEV. Keep later setup failures unchanged so real FF-A
initialisation problems are still reported as probe failures.

Reported-by: Nathan Chancellor <nathan at kernel.org>
Closes: https://lore.kernel.org/all/20260523001148.GA1319283@ax162
Signed-off-by: Sudeep Holla <sudeep.holla at kernel.org>
---
 drivers/firmware/arm_ffa/driver.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 54984e1b9741..0f468362c288 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -2109,7 +2109,7 @@ static int ffa_probe(struct platform_device *pdev)
 
 	ret = ffa_transport_init(&invoke_ffa_fn);
 	if (ret)
-		return ret;
+		return ret == -EOPNOTSUPP ? -ENODEV : ret;
 
 	drv_info = kzalloc_obj(*drv_info);
 	if (!drv_info)
@@ -2117,8 +2117,11 @@ static int ffa_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, drv_info);
 
 	ret = ffa_version_check(&drv_info->version);
-	if (ret)
+	if (ret) {
+		if (ret == -EOPNOTSUPP)
+			ret = -ENODEV;
 		goto free_drv_info;
+	}
 
 	if (ffa_id_get(&drv_info->vm_id)) {
 		pr_err("failed to obtain VM id for self\n");
-- 
2.43.0