From: William Breathitt Gray Date: Thu, 2 Jun 2016 20:00:09 +0000 (-0400) Subject: gpio: 104-dio-48e: Fix control port offset computation off-by-one error X-Git-Tag: v4.7-rc3~3^2~6 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d15d6cf91695674fbabac3b1d2c8a269d9bab5c6;p=karo-tx-linux.git gpio: 104-dio-48e: Fix control port offset computation off-by-one error There are only two control ports, each controlling three distinct I/O ports. To compute the control port address offset for a respective I/O port, the I/O port address offset should be divided by 3; dividing by 2 may result in not only the wrong address offset but possibly also an out-of-bounds array memory access for a non-existent third control port. Fixes: 1b06d64f7374 ("gpio: Add GPIO support for the ACCES 104-DIO-48E") Signed-off-by: William Breathitt Gray Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c index 1a647c07be67..fcf776971ca9 100644 --- a/drivers/gpio/gpio-104-dio-48e.c +++ b/drivers/gpio/gpio-104-dio-48e.c @@ -75,7 +75,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; - const unsigned control_port = io_port / 2; + const unsigned int control_port = io_port / 3; const unsigned control_addr = dio48egpio->base + 3 + control_port*4; unsigned long flags; unsigned control; @@ -115,7 +115,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset, { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; - const unsigned control_port = io_port / 2; + const unsigned int control_port = io_port / 3; const unsigned mask = BIT(offset % 8); const unsigned control_addr = dio48egpio->base + 3 + control_port*4; const unsigned out_port = (io_port > 2) ? io_port + 1 : io_port;