[PATCH v5 23/25] soundwire: amd: check for NULL manager drvdata in sdw_amd_startup()

[Vijendar Mukunda <Vijendar.Mukunda@amd.com>]

sdw_amd_startup() calls dev_get_drvdata() to retrieve the per-manager
context and passes the result unconditionally to amd_sdw_manager_start().
If the platform device for a manager instance was registered successfully
but its probe failed (e.g. due to ENOMEM or a deferred probe),
dev_get_drvdata() returns NULL and amd_sdw_manager_start() immediately
dereferences it, causing a kernel panic.

Add a NULL check after dev_get_drvdata() and return -ENODEV so that a
failed manager probe surfaces as an error from sdw_amd_probe() rather
than a kernel crash.

Fixes: ed5e8741b8db ("soundwire: amd: refactor amd soundwire manager device node creation")
Reported-by: Lee Jones <lee@kernel.org>
Closes: https://sashiko.dev/#/bug/linux-6834a8a0-632f-4c73-9174-0fe7e06b5303
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
---
 drivers/soundwire/amd_init.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/soundwire/amd_init.c b/drivers/soundwire/amd_init.c
index ce40b1e5dbf3..e5e6c7415dc6 100644
--- a/drivers/soundwire/amd_init.c
+++ b/drivers/soundwire/amd_init.c
@@ -166,6 +166,10 @@ static int sdw_amd_startup(struct sdw_amd_ctx *ctx)
 		if (!(ctx->link_mask & BIT(i)))
 			continue;
 		amd_manager = dev_get_drvdata(&ctx->pdev[i]->dev);
+		if (!amd_manager) {
+			dev_err(&ctx->pdev[i]->dev, "SoundWire manager not probed\n");
+			return -ENODEV;
+		}
 		ret = amd_sdw_manager_start(amd_manager);
 		if (ret)
 			return ret;
-- 
2.53.0