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, 15 insertions, 15 deletions

diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
index 23d447e17a67..df563616f943 100644
--- a/drivers/gpio/gpio-grgpio.c
+++ b/drivers/gpio/gpio-grgpio.c
@@ -145,7 +145,7 @@ static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	ipol = priv->gc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
 	iedge = priv->gc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;
@@ -153,7 +153,7 @@ static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
 	priv->gc.write_reg(priv->regs + GRGPIO_IPOL, ipol | pol);
 	priv->gc.write_reg(priv->regs + GRGPIO_IEDGE, iedge | edge);
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 
 	return 0;
 }
@@ -164,11 +164,11 @@ static void grgpio_irq_mask(struct irq_data *d)
 	int offset = d->hwirq;
 	unsigned long flags;
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	grgpio_set_imask(priv, offset, 0);
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 }
 
 static void grgpio_irq_unmask(struct irq_data *d)
@@ -177,11 +177,11 @@ static void grgpio_irq_unmask(struct irq_data *d)
 	int offset = d->hwirq;
 	unsigned long flags;
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	grgpio_set_imask(priv, offset, 1);
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 }
 
 static struct irq_chip grgpio_irq_chip = {
@@ -199,7 +199,7 @@ static irqreturn_t grgpio_irq_handler(int irq, void *dev)
 	int i;
 	int match = 0;
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	/*
 	 * For each gpio line, call its interrupt handler if it its underlying
@@ -215,7 +215,7 @@ static irqreturn_t grgpio_irq_handler(int irq, void *dev)
 		}
 	}
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 
 	if (!match)
 		dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);
@@ -247,13 +247,13 @@ static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
 	dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
 		irq, offset);
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	/* Request underlying irq if not already requested */
 	lirq->irq = irq;
 	uirq = &priv->uirqs[lirq->index];
 	if (uirq->refcnt == 0) {
-		spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+		raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 		ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
 				  dev_name(priv->dev), priv);
 		if (ret) {
@@ -262,11 +262,11 @@ static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
 				uirq->uirq);
 			return ret;
 		}
-		spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+		raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 	}
 	uirq->refcnt++;
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 
 	/* Setup irq  */
 	irq_set_chip_data(irq, priv);
@@ -290,7 +290,7 @@ static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 	irq_set_chip_and_handler(irq, NULL, NULL);
 	irq_set_chip_data(irq, NULL);
 
-	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+	raw_spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
 
 	/* Free underlying irq if last user unmapped */
 	index = -1;
@@ -309,13 +309,13 @@ static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 		uirq = &priv->uirqs[lirq->index];
 		uirq->refcnt--;
 		if (uirq->refcnt == 0) {
-			spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+			raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 			free_irq(uirq->uirq, priv);
 			return;
 		}
 	}
 
-	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
 }
 
 static const struct irq_domain_ops grgpio_irq_domain_ops = {