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* [PATCH] gpio: rcar: Use raw_spinlock to protect register access
@ 2025-01-21 13:58 Niklas Söderlund
  2025-01-21 14:49 ` Geert Uytterhoeven
  2025-03-05 12:15 ` Bartosz Golaszewski
  0 siblings, 2 replies; 6+ messages in thread
From: Niklas Söderlund @ 2025-01-21 13:58 UTC (permalink / raw)
  To: Geert Uytterhoeven, Linus Walleij, Bartosz Golaszewski,
	linux-gpio, linux-renesas-soc
  Cc: Niklas Söderlund

Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.

    [    4.239592] =============================
    [    4.239595] [ BUG: Invalid wait context ]
    [    4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 Not tainted
    [    4.239603] -----------------------------
    [    4.239606] kworker/u8:5/76 is trying to lock:
    [    4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.239641] other info that might help us debug this:
    [    4.239643] context-{5:5}
    [    4.239646] 5 locks held by kworker/u8:5/76:
    [    4.239651]  #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
    [    4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.254094]  #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
    [    4.254109]  #2: ffff00000920c8f8
    [    4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
    [    4.264803]  (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
    [    4.264820]  #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
    [    4.264840]  #4:
    [    4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
    [    4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
    [    4.304082] stack backtrace:
    [    4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35
    [    4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
    [    4.304097] Workqueue: async async_run_entry_fn
    [    4.304106] Call trace:
    [    4.304110]  show_stack+0x14/0x20 (C)
    [    4.304122]  dump_stack_lvl+0x6c/0x90
    [    4.304131]  dump_stack+0x14/0x1c
    [    4.304138]  __lock_acquire+0xdfc/0x1584
    [    4.426274]  lock_acquire+0x1c4/0x33c
    [    4.429942]  _raw_spin_lock_irqsave+0x5c/0x80
    [    4.434307]  gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.440061]  gpio_rcar_irq_set_type+0xd4/0xd8
    [    4.444422]  __irq_set_trigger+0x5c/0x178
    [    4.448435]  __setup_irq+0x2e4/0x690
    [    4.452012]  request_threaded_irq+0xc4/0x190
    [    4.456285]  devm_request_threaded_irq+0x7c/0xf4
    [    4.459398] ata1: link resume succeeded after 1 retries
    [    4.460902]  mmc_gpiod_request_cd_irq+0x68/0xe0
    [    4.470660]  mmc_start_host+0x50/0xac
    [    4.474327]  mmc_add_host+0x80/0xe4
    [    4.477817]  tmio_mmc_host_probe+0x2b0/0x440
    [    4.482094]  renesas_sdhi_probe+0x488/0x6f4
    [    4.486281]  renesas_sdhi_internal_dmac_probe+0x60/0x78
    [    4.491509]  platform_probe+0x64/0xd8
    [    4.495178]  really_probe+0xb8/0x2a8
    [    4.498756]  __driver_probe_device+0x74/0x118
    [    4.503116]  driver_probe_device+0x3c/0x154
    [    4.507303]  __device_attach_driver+0xd4/0x160
    [    4.511750]  bus_for_each_drv+0x84/0xe0
    [    4.515588]  __device_attach_async_helper+0xb0/0xdc
    [    4.520470]  async_run_entry_fn+0x30/0xd8
    [    4.524481]  process_one_work+0x210/0x62c
    [    4.528494]  worker_thread+0x1ac/0x340
    [    4.532245]  kthread+0x10c/0x110
    [    4.535476]  ret_from_fork+0x10/0x20

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---

Hi Geert,

This is similar to what was done to other GPIO drivers to solve the same
situation see [1], [2], [3] and [4] for some examples.

1. 3c938cc5cebc ("gpio: use raw spinlock for gpio chip shadowed data")
2. 37174f334130 ("gpio: tegra: Use raw_spinlock")
3. 4dbada2be460 ("gpio: omap: use raw locks for locking")
3. 505936131ea7 ("gpio: mpc8xxx: Convert mpc8xxx_gpio_chip.lock to raw_spinlock")
---
 drivers/gpio/gpio-rcar.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
index 2ecee3269a0c..8e0544e92488 100644
--- a/drivers/gpio/gpio-rcar.c
+++ b/drivers/gpio/gpio-rcar.c
@@ -40,7 +40,7 @@ struct gpio_rcar_info {
 
 struct gpio_rcar_priv {
 	void __iomem *base;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	struct device *dev;
 	struct gpio_chip gpio_chip;
 	unsigned int irq_parent;
@@ -123,7 +123,7 @@ static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
 	 * "Setting Level-Sensitive Interrupt Input Mode"
 	 */
 
-	spin_lock_irqsave(&p->lock, flags);
+	raw_spin_lock_irqsave(&p->lock, flags);
 
 	/* Configure positive or negative logic in POSNEG */
 	gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
@@ -142,7 +142,7 @@ static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
 	if (!level_trigger)
 		gpio_rcar_write(p, INTCLR, BIT(hwirq));
 
-	spin_unlock_irqrestore(&p->lock, flags);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
 }
 
 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
@@ -246,7 +246,7 @@ static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
 	 * "Setting General Input Mode"
 	 */
 
-	spin_lock_irqsave(&p->lock, flags);
+	raw_spin_lock_irqsave(&p->lock, flags);
 
 	/* Configure positive logic in POSNEG */
 	gpio_rcar_modify_bit(p, POSNEG, gpio, false);
@@ -261,7 +261,7 @@ static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
 	if (p->info.has_outdtsel && output)
 		gpio_rcar_modify_bit(p, OUTDTSEL, gpio, false);
 
-	spin_unlock_irqrestore(&p->lock, flags);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
 }
 
 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
@@ -347,7 +347,7 @@ static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask,
 		return 0;
 	}
 
-	spin_lock_irqsave(&p->lock, flags);
+	raw_spin_lock_irqsave(&p->lock, flags);
 	outputs = gpio_rcar_read(p, INOUTSEL);
 	m = outputs & bankmask;
 	if (m)
@@ -356,7 +356,7 @@ static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask,
 	m = ~outputs & bankmask;
 	if (m)
 		val |= gpio_rcar_read(p, INDT) & m;
-	spin_unlock_irqrestore(&p->lock, flags);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
 
 	bits[0] = val;
 	return 0;
@@ -367,9 +367,9 @@ static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
 	unsigned long flags;
 
-	spin_lock_irqsave(&p->lock, flags);
+	raw_spin_lock_irqsave(&p->lock, flags);
 	gpio_rcar_modify_bit(p, OUTDT, offset, value);
-	spin_unlock_irqrestore(&p->lock, flags);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
 }
 
 static void gpio_rcar_set_multiple(struct gpio_chip *chip, unsigned long *mask,
@@ -386,12 +386,12 @@ static void gpio_rcar_set_multiple(struct gpio_chip *chip, unsigned long *mask,
 	if (!bankmask)
 		return;
 
-	spin_lock_irqsave(&p->lock, flags);
+	raw_spin_lock_irqsave(&p->lock, flags);
 	val = gpio_rcar_read(p, OUTDT);
 	val &= ~bankmask;
 	val |= (bankmask & bits[0]);
 	gpio_rcar_write(p, OUTDT, val);
-	spin_unlock_irqrestore(&p->lock, flags);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
 }
 
 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
@@ -505,7 +505,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	p->dev = dev;
-	spin_lock_init(&p->lock);
+	raw_spin_lock_init(&p->lock);
 
 	/* Get device configuration from DT node */
 	ret = gpio_rcar_parse_dt(p, &npins);
-- 
2.48.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-03-05 12:15 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-01-21 13:58 [PATCH] gpio: rcar: Use raw_spinlock to protect register access Niklas Söderlund
2025-01-21 14:49 ` Geert Uytterhoeven
2025-01-21 15:03   ` Claudiu Beznea
2025-01-22 17:27   ` Niklas Söderlund
2025-03-04 16:02     ` Geert Uytterhoeven
2025-03-05 12:15 ` Bartosz Golaszewski

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