gpio: use raw spinlock for gpio chip shadowed data

In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency
as the lockdep report shows.

__irq_set_handler
  irq_get_desc_buslock
    __irq_get_desc_lock
      raw_spin_lock_irqsave(&desc->lock, *flags);  // raw spinlock get here
  __irq_do_set_handler
    mask_ack_irq
      dwapb_irq_ack
        spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock
  irq_put_desc_busunlock

Replace with a raw lock to avoid BUGs. This lock is only used to access
registers, and It's safe to replace with the raw lock without bad
influence.

[   15.090359][    T1] =============================
[   15.090365][    T1] [ BUG: Invalid wait context ]
[   15.090373][    T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted
[   15.090386][    T1] -----------------------------
[   15.090392][    T1] swapper/0/1 is trying to lock:
[   15.090402][    T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090470][    T1] other info that might help us debug this:
[   15.090477][    T1] context-{5:5}
[   15.090485][    T1] 3 locks held by swapper/0/1:
[   15.090497][    T1]  #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104
[   15.090553][    T1]  #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4
[   15.090606][    T1]  #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090654][    T1] stack backtrace:
[   15.090661][    T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3
[   15.090682][    T1] Hardware name: Horizon Robotics Journey 5 DVB (DT)
[   15.090692][    T1] Call trace:
......
[   15.090811][    T1]  _raw_spin_lock_irqsave+0x1c/0x28
[   15.090828][    T1]  dwapb_irq_ack+0xb4/0x300
[   15.090846][    T1]  __irq_do_set_handler+0x494/0xb2c
[   15.090864][    T1]  __irq_set_handler+0x74/0x114
[   15.090881][    T1]  irq_set_chip_and_handler_name+0x44/0x58
[   15.090900][    T1]  gpiochip_irq_map+0x210/0x644

Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Doug Berger <opendmb@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

1 files changed, 9 insertions, 9 deletions

diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c
index 3d89912a05b8..64cb060d9d75 100644
--- a/drivers/gpio/gpio-mlxbf2.c
+++ b/drivers/gpio/gpio-mlxbf2.c
@@ -131,7 +131,7 @@ static int mlxbf2_gpio_lock_acquire(struct mlxbf2_gpio_context *gs)
 	u32 arm_gpio_lock_val;
 
 	mutex_lock(yu_arm_gpio_lock_param.lock);
-	spin_lock(&gs->gc.bgpio_lock);
+	raw_spin_lock(&gs->gc.bgpio_lock);
 
 	arm_gpio_lock_val = readl(yu_arm_gpio_lock_param.io);
 
@@ -139,7 +139,7 @@ static int mlxbf2_gpio_lock_acquire(struct mlxbf2_gpio_context *gs)
 	 * When lock active bit[31] is set, ModeX is write enabled
 	 */
 	if (YU_LOCK_ACTIVE_BIT(arm_gpio_lock_val)) {
-		spin_unlock(&gs->gc.bgpio_lock);
+		raw_spin_unlock(&gs->gc.bgpio_lock);
 		mutex_unlock(yu_arm_gpio_lock_param.lock);
 		return -EINVAL;
 	}
@@ -157,7 +157,7 @@ static void mlxbf2_gpio_lock_release(struct mlxbf2_gpio_context *gs)
 	__releases(yu_arm_gpio_lock_param.lock)
 {
 	writel(YU_ARM_GPIO_LOCK_RELEASE, yu_arm_gpio_lock_param.io);
-	spin_unlock(&gs->gc.bgpio_lock);
+	raw_spin_unlock(&gs->gc.bgpio_lock);
 	mutex_unlock(yu_arm_gpio_lock_param.lock);
 }
 
@@ -237,7 +237,7 @@ static void mlxbf2_gpio_irq_enable(struct irq_data *irqd)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
 	val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE);
 	val |= BIT(offset);
 	writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE);
@@ -245,7 +245,7 @@ static void mlxbf2_gpio_irq_enable(struct irq_data *irqd)
 	val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
 	val |= BIT(offset);
 	writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
-	spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
 }
 
 static void mlxbf2_gpio_irq_disable(struct irq_data *irqd)
@@ -256,11 +256,11 @@ static void mlxbf2_gpio_irq_disable(struct irq_data *irqd)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
 	val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
 	val &= ~BIT(offset);
 	writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
-	spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
 }
 
 static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr)
@@ -307,7 +307,7 @@ mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
 	if (fall) {
 		val = readl(gs->gpio_io + YU_GPIO_CAUSE_FALL_EN);
 		val |= BIT(offset);
@@ -319,7 +319,7 @@ mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
 		val |= BIT(offset);
 		writel(val, gs->gpio_io + YU_GPIO_CAUSE_RISE_EN);
 	}
-	spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
 
 	return 0;
 }