From 27d9098cff6e7491617890d0e93632181a532ff3 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Thu, 16 Jun 2016 11:25:36 +0300 Subject: [PATCH] pinctrl: intel: Use raw_spinlock for locking When running -rt kernel and GPIO interrupt happens we get following BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 in_atomic(): 1, irqs_disabled(): 0, pid: 530, name: irq/14-INT3452: Preemption disabled at:[] handle_edge_irq+0x1b/0x190 CPU: 0 PID: 530 Comm: irq/14-INT3452: Not tainted 4.6.2-rt5 #1060 0000000000000000 ffff88007a257d58 ffffffff812d8494 0000000000000000 ffff88017a330000 ffff88007a257d78 ffffffff81083a11 ffff88007a252430 ffff88007a252430 ffff88007a257d90 ffffffff8167ef20 000000000000001a Call Trace: [] dump_stack+0x4f/0x6b [] ___might_sleep+0xe1/0x160 [] rt_spin_lock+0x20/0x50 [] intel_gpio_irq_ack+0x2d/0x80 [] handle_edge_irq+0x7b/0x190 [] generic_handle_irq+0x22/0x30 [] intel_gpio_irq+0xdc/0x150 [] irq_forced_thread_fn+0x23/0x70 [] irq_thread+0x13b/0x1d0 [] ? __schedule+0x2e4/0x5a0 [] ? irq_finalize_oneshot.part.37+0xd0/0xd0 [] ? irq_thread+0x1d0/0x1d0 [] ? wake_threads_waitq+0x30/0x30 [] kthread+0xd4/0xf0 [] ? _raw_spin_unlock_irq+0x17/0x40 [] ret_from_fork+0x22/0x40 [] ? kthread_worker_fn+0x190/0x190 The reason why this happens is because intel_gpio_irq_ack() is called with desc->lock raw_spinlock locked which cannot sleep but our normal spinlock (which is converted to rtmutex in -rt) is allowed to sleep. This causes might_sleep() to trigger. Fix this by converting the normal spinlock to a raw_spinlock. Reported-by: Kim Tatt Chuah Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/pinctrl/intel/pinctrl-intel.c | 44 +++++++++++++-------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c index 3584e50fa2c6..f1b14f256001 100644 --- a/drivers/pinctrl/intel/pinctrl-intel.c +++ b/drivers/pinctrl/intel/pinctrl-intel.c @@ -89,7 +89,7 @@ struct intel_pinctrl_context { */ struct intel_pinctrl { struct device *dev; - spinlock_t lock; + raw_spinlock_t lock; struct pinctrl_desc pctldesc; struct pinctrl_dev *pctldev; struct gpio_chip chip; @@ -318,7 +318,7 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function, unsigned long flags; int i; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); /* * All pins in the groups needs to be accessible and writable @@ -326,7 +326,7 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function, */ for (i = 0; i < grp->npins; i++) { if (!intel_pad_usable(pctrl, grp->pins[i])) { - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EBUSY; } } @@ -345,7 +345,7 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function, writel(value, padcfg0); } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -359,10 +359,10 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev, unsigned long flags; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); if (!intel_pad_usable(pctrl, pin)) { - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EBUSY; } @@ -377,7 +377,7 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev, value |= PADCFG0_GPIOTXDIS; writel(value, padcfg0); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -391,7 +391,7 @@ static int intel_gpio_set_direction(struct pinctrl_dev *pctldev, unsigned long flags; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0); @@ -402,7 +402,7 @@ static int intel_gpio_set_direction(struct pinctrl_dev *pctldev, value &= ~PADCFG0_GPIOTXDIS; writel(value, padcfg0); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -490,7 +490,7 @@ static int intel_config_set_pull(struct intel_pinctrl *pctrl, unsigned pin, int ret = 0; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); padcfg1 = intel_get_padcfg(pctrl, pin, PADCFG1); value = readl(padcfg1); @@ -544,7 +544,7 @@ static int intel_config_set_pull(struct intel_pinctrl *pctrl, unsigned pin, if (!ret) writel(value, padcfg1); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return ret; } @@ -611,14 +611,14 @@ static void intel_gpio_set(struct gpio_chip *chip, unsigned offset, int value) unsigned long flags; u32 padcfg0; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); padcfg0 = readl(reg); if (value) padcfg0 |= PADCFG0_GPIOTXSTATE; else padcfg0 &= ~PADCFG0_GPIOTXSTATE; writel(padcfg0, reg); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } } @@ -651,7 +651,7 @@ static void intel_gpio_irq_ack(struct irq_data *d) const struct intel_community *community; unsigned pin = irqd_to_hwirq(d); - spin_lock(&pctrl->lock); + raw_spin_lock(&pctrl->lock); community = intel_get_community(pctrl, pin); if (community) { @@ -662,7 +662,7 @@ static void intel_gpio_irq_ack(struct irq_data *d) writel(BIT(gpp_offset), community->regs + GPI_IS + gpp * 4); } - spin_unlock(&pctrl->lock); + raw_spin_unlock(&pctrl->lock); } static void intel_gpio_irq_enable(struct irq_data *d) @@ -673,7 +673,7 @@ static void intel_gpio_irq_enable(struct irq_data *d) unsigned pin = irqd_to_hwirq(d); unsigned long flags; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); community = intel_get_community(pctrl, pin); if (community) { @@ -691,7 +691,7 @@ static void intel_gpio_irq_enable(struct irq_data *d) writel(value, community->regs + community->ie_offset + gpp * 4); } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask) @@ -702,7 +702,7 @@ static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask) unsigned pin = irqd_to_hwirq(d); unsigned long flags; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); community = intel_get_community(pctrl, pin); if (community) { @@ -721,7 +721,7 @@ static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask) writel(value, reg); } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } static void intel_gpio_irq_mask(struct irq_data *d) @@ -757,7 +757,7 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned type) return -EPERM; } - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); value = readl(reg); @@ -784,7 +784,7 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned type) else if (type & IRQ_TYPE_LEVEL_MASK) irq_set_handler_locked(d, handle_level_irq); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -995,7 +995,7 @@ int intel_pinctrl_probe(struct platform_device *pdev, pctrl->dev = &pdev->dev; pctrl->soc = soc_data; - spin_lock_init(&pctrl->lock); + raw_spin_lock_init(&pctrl->lock); /* * Make a copy of the communities which we can use to hold pointers -- 2.20.1