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: b888fb6f2a27 ("gpio: stmpe: i2c transfer are forbiden in atomic context")
Cc: stable@xxxxxxxxxxxxxxx # 4.16+
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
drivers/gpio/gpio-stmpe.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index 75a3633ceddb..222279a9d82b 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -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);
}
--
2.42.0.windows.2
