[PATCH 4.9 45/56] gpio: adnp: Fix testing wrong value in adnp_gpio_direction_input

From: Greg Kroah-Hartman
Date: Mon Apr 01 2019 - 13:28:27 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Axel Lin <axel.lin@xxxxxxxxxx>

commit c5bc6e526d3f217ed2cc3681d256dc4a2af4cc2b upstream.

Current code test wrong value so it does not verify if the written
data is correctly read back. Fix it.
Also make it return -EPERM if read value does not match written bit,
just like it done for adnp_gpio_direction_output().

Fixes: 5e969a401a01 ("gpio: Add Avionic Design N-bit GPIO expander support")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
Reviewed-by: Thierry Reding <thierry.reding@xxxxxxxxx>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpio/gpio-adnp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpio/gpio-adnp.c
+++ b/drivers/gpio/gpio-adnp.c
@@ -132,8 +132,10 @@ static int adnp_gpio_direction_input(str
if (err < 0)
goto out;

- if (err & BIT(pos))
- err = -EACCES;
+ if (value & BIT(pos)) {
+ err = -EPERM;
+ goto out;
+ }

err = 0;