Commit 87041a58 authored by Colin Pitrat's avatar Colin Pitrat Committed by Linus Walleij
Browse files

gpio: sch: Fix Oops on module load on Asus Eee PC 1201 

This fixes the issue descirbe in bug 117531
(https://bugzilla.kernel.org/show_bug.cgi?id=117531).
It's a regression introduced in linux 4.5 that causes a Oops at load of
gpio_sch and prevents powering off the computer.

The issue is that sch_gpio_reg_set is called in sch_gpio_probe before
gpio_chip data is initialized with the pointer to the sch_gpio struct. As
sch_gpio_reg_set calls gpiochip_get_data, it returns NULL which causes
the Oops.

The patch follows Mika's advice (https://lkml.org/lkml/2016/5/9/61

) and
consists in modifying sch_gpio_reg_get and sch_gpio_reg_set to take a
sch_gpio struct directly instead of a gpio_chip, which avoids the call to
gpiochip_get_data.

Thanks Mika for your patience with me :-)

Cc: stable@vger.kernel.org
Signed-off-by: default avatarColin Pitrat <colin.pitrat@gmail.com>
Acked-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent a99cde43

drivers/gpio/gpio-sch.c

+10 −11
Original line number Diff line number Diff line
@@ -61,9 +61,8 @@ static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio) 
	return gpio % 8;

}



static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg)

static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned gpio, unsigned reg)

{

	struct sch_gpio *sch = gpiochip_get_data(gc);

	unsigned short offset, bit;

	u8 reg_val;
@@ -75,10 +74,9 @@ static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg) 
	return reg_val;

}



static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg,

static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio, unsigned reg,

			     int val)

{

	struct sch_gpio *sch = gpiochip_get_data(gc);

	unsigned short offset, bit;

	u8 reg_val;
@@ -98,14 +96,15 @@ static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num) 
	struct sch_gpio *sch = gpiochip_get_data(gc);



	spin_lock(&sch->lock);

	sch_gpio_reg_set(gc, gpio_num, GIO, 1);

	sch_gpio_reg_set(sch, gpio_num, GIO, 1);

	spin_unlock(&sch->lock);

	return 0;

}



static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)

{

	return sch_gpio_reg_get(gc, gpio_num, GLV);

	struct sch_gpio *sch = gpiochip_get_data(gc);

	return sch_gpio_reg_get(sch, gpio_num, GLV);

}



static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
@@ -113,7 +112,7 @@ static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val) 
	struct sch_gpio *sch = gpiochip_get_data(gc);



	spin_lock(&sch->lock);

	sch_gpio_reg_set(gc, gpio_num, GLV, val);

	sch_gpio_reg_set(sch, gpio_num, GLV, val);

	spin_unlock(&sch->lock);

}
@@ -123,7 +122,7 @@ static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num, 
	struct sch_gpio *sch = gpiochip_get_data(gc);



	spin_lock(&sch->lock);

	sch_gpio_reg_set(gc, gpio_num, GIO, 0);

	sch_gpio_reg_set(sch, gpio_num, GIO, 0);

	spin_unlock(&sch->lock);



	/*
@@ -182,13 +181,13 @@ static int sch_gpio_probe(struct platform_device *pdev) 
		 * GPIO7 is configured by the CMC as SLPIOVR

		 * Enable GPIO[9:8] core powered gpios explicitly

		 */

		sch_gpio_reg_set(&sch->chip, 8, GEN, 1);

		sch_gpio_reg_set(&sch->chip, 9, GEN, 1);

		sch_gpio_reg_set(sch, 8, GEN, 1);

		sch_gpio_reg_set(sch, 9, GEN, 1);

		/*

		 * SUS_GPIO[2:0] enabled by default

		 * Enable SUS_GPIO3 resume powered gpio explicitly

		 */

		sch_gpio_reg_set(&sch->chip, 13, GEN, 1);

		sch_gpio_reg_set(sch, 13, GEN, 1);

		break;



	case PCI_DEVICE_ID_INTEL_ITC_LPC:

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