[PATCH v2] serial: 8250_dw: handle reset control deassert error

[Artem Shimko <a.shimko.dev@gmail.com>]

Check the return value of reset_control_deassert() in the probe
function to prevent continuing probe when reset deassertion fails.

Previously, reset_control_deassert() was called without checking its
return value, which could lead to probe continuing even when the
device reset wasn't properly deasserted.

The fix checks the return value and returns an error with dev_err_probe()
if reset deassertion fails, providing better error handling and
diagnostics.

Fixes: acbdad8dd1ab ("serial: 8250_dw: simplify optional reset handling")
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
---
Hi Andy,

Thank you for your review.

The v1 patch hasn't been applied.

I've addressed your comments in v2 - could you please take a look when you have time?

Best regards,
Artem Shimko

ChangeLog:
  v1:
    * https://lore.kernel.org/all/20251009081309.2021600-1-a.shimko.dev@gmail.com/T/#u
  v2:
    * Add fix tag to commit description

 drivers/tty/serial/8250/8250_dw.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a53ba04d9770..710ae4d40aec 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -635,7 +635,9 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (IS_ERR(data->rst))
 		return PTR_ERR(data->rst);
 
-	reset_control_deassert(data->rst);
+	err = reset_control_deassert(data->rst);
+	if (err)
+		return dev_err_probe(dev, err, "failed to deassert resets\n");
 
 	err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
 	if (err)
-- 
2.43.0