Commit b9644fbf authored by Wentao Liang's avatar Wentao Liang Committed by Bartosz Golaszewski
Browse files

gpio: stmpe: Check return value of stmpe_reg_read in stmpe_gpio_irq_sync_unlock 



The stmpe_reg_read function can fail, but its return value is not checked
in stmpe_gpio_irq_sync_unlock. This can lead to silent failures and
incorrect behavior if the hardware access fails.

This patch adds checks for the return value of stmpe_reg_read. If the
function fails, an error message is logged and the function returns
early to avoid further issues.

Fixes: b888fb6f ("gpio: stmpe: i2c transfer are forbiden in atomic context")
Cc: stable@vger.kernel.org # 4.16+
Signed-off-by: default avatarWentao Liang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20250212021849.275-1-vulab@iscas.ac.cn


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 8743d669

drivers/gpio/gpio-stmpe.c

+12 −3
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d) 
		[REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB,

		[REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB,

	};

	int i, j;

	int ret, i, j;



	/*

	 * STMPE1600: to be able to get IRQ from pins,
@@ -199,8 +199,16 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d) 
	 * GPSR or GPCR registers

	 */

	if (stmpe->partnum == STMPE1600) {

		stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]);

		stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]);

		ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]);

		if (ret < 0) {

			dev_err(stmpe->dev, "Failed to read GPMR_LSB: %d\n", ret);

			goto err;

		}

		ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]);

		if (ret < 0) {

			dev_err(stmpe->dev, "Failed to read GPMR_CSB: %d\n", ret);

			goto err;

		}

	}



	for (i = 0; i < CACHE_NR_REGS; i++) {
@@ -222,6 +230,7 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d) 
		}

	}



err:

	mutex_unlock(&stmpe_gpio->irq_lock);

}