[PATCH] gpio: omap: handle clk_prepare failure in probe

[Jiawen Liu]

omap_gpio_probe() ignores the return value of clk_prepare(bank->dbck).
If clk_prepare fails, the clock is not prepared, but bank->dbck_flag
remains true. Later, omap_gpio_remove() or the probe error path calls
clk_unprepare(bank->dbck) unconditionally when dbck_flag is true,
leading to an unbalanced clock operation.

Check the return value of clk_prepare in omap_gpio_probe. On failure,
clear dbck_flag and return the error, preventing unbalanced
clk_unprepare in remove or error paths.

Signed-off-by: jiawen <1298662399@xxxxxx>
---
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1462,7 +1462,12 @@
 				"Could not get gpio dbck. Disable debounce\n");
 			bank->dbck_flag = false;
 		} else {
-			clk_prepare(bank->dbck);
+			ret = clk_prepare(bank->dbck);
+			if (ret) {
+				dev_err(dev, "Could not prepare gpio dbck\n");
+				bank->dbck_flag = false;
+				return ret;
+			}
 		}
 	}