[PATCH] i2c: designware-platdrv: handle reset control deassert error

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

Handle the error returned by 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.

Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
---
Hello maintainers and reviewers,

This patch adds proper error handling for reset_control_deassert() in the 
DesignWare I2C platform driver probe function.

Currently, if reset deassertion fails, the driver continues probing which
could lead to operating a device that is still held in reset. This patch
ensures we properly check the return value and fail the probe with a
meaningful error message if reset deassertion fails.

The change is safe because:
1. reset_control_deassert() handles NULL pointers (for optional resets) 
   by returning 0 (success)
2. For non-NULL reset controls, we now properly validate the operation
3. dev_err_probe() provides appropriate error context for diagnostics

Thank you for your consideration.

Best regards,
Artem Shimko

 drivers/i2c/busses/i2c-designware-platdrv.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index a35e4c64a1d4..4c57c79d4ce5 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -240,7 +240,9 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	if (IS_ERR(dev->rst))
 		return PTR_ERR(dev->rst);
 
-	reset_control_deassert(dev->rst);
+	ret = reset_control_deassert(dev->rst);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to deassert reset\n");
 
 	ret = i2c_dw_fw_parse_and_configure(dev);
 	if (ret)
-- 
2.43.0