linux-kernel - [PATCH] gpio: sch: Fix Oops on module load on Asus Eee PC 1201

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Date:	Fri, 6 May 2016 22:49:25 +0100
From:	Colin Pitrat <colin.pitrat@...il.com>
To:	linus.walleij@...aro.org, gnurou@...il.com
Cc:	rebecca.swee.fun.chang@...el.com, mika.westerberg@...ux.intel.com,
	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] gpio: sch: Fix Oops on module load on Asus Eee PC 1201

This fixes the issue descirbe in bug 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 patch consist in reverting commit 737c8fccf1c5b2aae3c6d9a66dce17e35fc39b71 
(a.k.a 'gpio: sch: use gpiochip data pointer') that causes this regression.
However, although it does work for me, I'm not sure of the impact of reverting
only this part of the patch.

Signed-off-by: Colin Pitrat <colin.pitrat@...il.com>

---
 drivers/gpio/gpio-sch.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
index e85e753..a8a333ad 100644
--- a/drivers/gpio/gpio-sch.c
+++ b/drivers/gpio/gpio-sch.c
@@ -41,6 +41,8 @@ struct sch_gpio {
 	unsigned short resume_base;
 };
 
+#define to_sch_gpio(gc)	container_of(gc, struct sch_gpio, chip)
+
 static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio,
 				unsigned reg)
 {
@@ -63,7 +65,7 @@ static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio)
 
 static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg)
 {
-	struct sch_gpio *sch = gpiochip_get_data(gc);
+	struct sch_gpio *sch = to_sch_gpio(gc);
 	unsigned short offset, bit;
 	u8 reg_val;
 
@@ -78,7 +80,7 @@ static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg)
 static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg,
 			     int val)
 {
-	struct sch_gpio *sch = gpiochip_get_data(gc);
+	struct sch_gpio *sch = to_sch_gpio(gc);
 	unsigned short offset, bit;
 	u8 reg_val;
 
@@ -95,7 +97,7 @@ static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg,
 
 static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
 {
-	struct sch_gpio *sch = gpiochip_get_data(gc);
+	struct sch_gpio *sch = to_sch_gpio(gc);
 
 	spin_lock(&sch->lock);
 	sch_gpio_reg_set(gc, gpio_num, GIO, 1);
@@ -110,7 +112,7 @@ static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
 
 static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
 {
-	struct sch_gpio *sch = gpiochip_get_data(gc);
+	struct sch_gpio *sch = to_sch_gpio(gc);
 
 	spin_lock(&sch->lock);
 	sch_gpio_reg_set(gc, gpio_num, GLV, val);
@@ -120,7 +122,7 @@ static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
 static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
 				  int val)
 {
-	struct sch_gpio *sch = gpiochip_get_data(gc);
+	struct sch_gpio *sch = to_sch_gpio(gc);
 
 	spin_lock(&sch->lock);
 	sch_gpio_reg_set(gc, gpio_num, GIO, 0);
@@ -215,7 +217,15 @@ static int sch_gpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sch);
 
-	return devm_gpiochip_add_data(&pdev->dev, &sch->chip, sch);
+	return gpiochip_add(&sch->chip);
+}
+
+static int sch_gpio_remove(struct platform_device *pdev)
+{
+	struct sch_gpio *sch = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&sch->chip);
+	return 0;
 }
 
 static struct platform_driver sch_gpio_driver = {
@@ -223,6 +233,7 @@ static struct platform_driver sch_gpio_driver = {
 		.name = "sch_gpio",
 	},
 	.probe		= sch_gpio_probe,
+	.remove		= sch_gpio_remove,
 };
 
 module_platform_driver(sch_gpio_driver);
-- 
2.8.2