[PATCH 4.9 07/59] gpio: adp5588: Fix sleep-in-atomic-context bug

Greg Kroah-Hartman
2018-10-08T18:38:45Z

From: Michael Hennerich <michael.hennerich@analog.com>

[ Upstream commit 6537886cdc9a637711fd6da980dbb87c2c87c9aa ]

This fixes:
[BUG] gpio: gpio-adp5588: A possible sleep-in-atomic-context bug
in adp5588_gpio_write()
[BUG] gpio: gpio-adp5588: A possible sleep-in-atomic-context bug
in adp5588_gpio_direction_input()

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpio/gpio-adp5588.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)

--- a/drivers/gpio/gpio-adp5588.c
+++ b/drivers/gpio/gpio-adp5588.c
@@ -41,6 +41,8 @@ struct adp5588_gpio {
uint8_t int_en[3];
uint8_t irq_mask[3];
uint8_t irq_stat[3];
+ uint8_t int_input_en[3];
+ uint8_t int_lvl_cached[3];
};

static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
@@ -173,12 +175,28 @@ static void adp5588_irq_bus_sync_unlock(
struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
int i;

- for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
+ for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
+ if (dev->int_input_en[i]) {
+ mutex_lock(&dev->lock);
+ dev->dir[i] &= ~dev->int_input_en[i];
+ dev->int_input_en[i] = 0;
+ adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
+ dev->dir[i]);
+ mutex_unlock(&dev->lock);
+ }
+
+ if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
+ dev->int_lvl_cached[i] = dev->int_lvl[i];
+ adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
+ dev->int_lvl[i]);
+ }
+
if (dev->int_en[i] ^ dev->irq_mask[i]) {
dev->int_en[i] = dev->irq_mask[i];
adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
dev->int_en[i]);
}
+ }

mutex_unlock(&dev->irq_lock);
}
@@ -221,9 +239,7 @@ static int adp5588_irq_set_type(struct i
else
return -EINVAL;

- adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
- adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
- dev->int_lvl[bank]);
+ dev->int_input_en[bank] |= bit;

return 0;
}