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Message-ID: <1464095903-29145-1-git-send-email-ldewangan@nvidia.com> Date: Tue, 24 May 2016 18:48:22 +0530 From: Laxman Dewangan <ldewangan@...dia.com> To: <linus.walleij@...aro.org>, <gnurou@...il.com> CC: <linux-gpio@...r.kernel.org>, <linux-kernel@...r.kernel.org>, "Laxman Dewangan" <ldewangan@...dia.com> Subject: [PATCH] gpio: core: Do not call get_direction in atomic context for sleeping gpio When adding the gpiochip, the GPIO HW drivers' callback get_direction() get called in atomic context. Some of the GPIO HW drivers can sleep when accessing the register and hence it can create the sleeping call in atomic context. Call get_direction() in non-atomic context from gpiochip_add() if GPIO HW driver is having sleepable callback i.e. chip->can_sleep = 1. Signed-off-by: Laxman Dewangan <ldewangan@...dia.com> --- This is found when implementing the get_direction() of max77620 on 20160520 linux-next. drivers/gpio/gpiolib.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d407f904..4d04171 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -636,7 +636,15 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) * If we have .get_direction, set up the initial * direction flag from the hardware. */ - int dir = chip->get_direction(chip, i); + int dir; + + if (chip->can_sleep) + spin_unlock_irqrestore(&gpio_lock, flags); + + dir = chip->get_direction(chip, i); + + if (chip->can_sleep) + spin_lock_irqsave(&gpio_lock, flags); if (!dir) set_bit(FLAG_IS_OUT, &desc->flags); -- 2.1.4
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