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authorFrancois Berder <Francois.Berder@imgtec.com>2016-10-25 13:24:13 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-27 16:42:31 +0200
commit03842c17397e14cb8bb1adc2015f5dce6c733ffe (patch)
treeda2b5574afe85eac58b3d82ed73fac98b8ead2da /drivers/tty
parentc03e1b8703a4a0c8bac7f6b65d8fcb539ec62d82 (diff)
sc16is7xx: always write state when configuring GPIO as an output
The regmap_update first reads the IOState register and then triggers a write if needed. However, GPIOS might be configured as an input so the read to IOState on this GPIO is the current state which might be random. Signed-off-by: Francois Berder <Francois.Berder@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/sc16is7xx.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 2675792a8f59..fb0672554123 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1130,9 +1130,13 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
{
struct sc16is7xx_port *s = gpiochip_get_data(chip);
struct uart_port *port = &s->p[0].port;
+ u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
- sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
- val ? BIT(offset) : 0);
+ if (val)
+ state |= BIT(offset);
+ else
+ state &= ~BIT(offset);
+ sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
BIT(offset));