[PATCH v4 1/8] iio: light: si1133: reset counter to prevent race condition

[Joshua Crofts via B4 Relay <devnull+joshua.crofts1.gmail.com@kernel.org>]

From: Joshua Crofts <joshua.crofts1@gmail.com>

Sashiko reported a potential race condition happening when the driver
returns an errno after a timeout in the si1133_command() function. The
premature exit causes the hardware and software counters to become out
of sync by not updating data->rsp_seq, therefore the internal hardware
counter keeps incrementing.

Fix this by adding a call to si1133_cmd_reset_counter() before returning
from timeout.

Fixes: e01e7eaf37d8 ("iio: light: introduce si1133")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/message/20260428-si1133-checkup-v2-5-70ad14bfefe2%40gmail.com
Assisted-by: gemini:gemini-3.1-pro-preview
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
---
 drivers/iio/light/si1133.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iio/light/si1133.c b/drivers/iio/light/si1133.c
index 44fa152dbd24c26c97cc778cbe641d92ecd56afa..c88c79202be2e21abb72067426e31b6bf97c61cf 100644
--- a/drivers/iio/light/si1133.c
+++ b/drivers/iio/light/si1133.c
@@ -427,6 +427,11 @@ static int si1133_command(struct si1133_data *data, u8 cmd)
 			dev_warn(dev,
 				 "Failed to read command 0x%02x, ret=%d\n",
 				 cmd, err);
+			/*
+			 * Reset counter on err to prevent software and hardware
+			 * counters being out of sync.
+			 */
+			si1133_cmd_reset_counter(data);
 			goto out;
 		}
 	}

-- 
2.47.3