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Commit 3d009c8c authored by Tony Lindgren's avatar Tony Lindgren Committed by Linus Walleij
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gpio: omap: Fix bad device access with setup_irq() 



Similar to omap_gpio_irq_type() let's make sure that the GPIO
is usable as an interrupt if the platform init code did not
call gpio_request(). Otherwise we can get invalid device access
after setup_irq():

WARNING: CPU: 0 PID: 1 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x214/0x340()
44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4CFG (Idle): Data Access in Supervisor mode during Functional access
...
[<c05f21e4>] (__irq_svc) from [<c05f1974>] (_raw_spin_unlock_irqrestore+0x34/0x44)
[<c05f1974>] (_raw_spin_unlock_irqrestore) from [<c00914a8>] (__setup_irq+0x244/0x530)
[<c00914a8>] (__setup_irq) from [<c00917d4>] (setup_irq+0x40/0x8c)
[<c00917d4>] (setup_irq) from [<c0039c8c>] (omap_system_dma_probe+0x1d4/0x2b4)
[<c0039c8c>] (omap_system_dma_probe) from [<c03b2200>] (platform_drv_probe+0x44/0xa4)
...

We can fix this the same way omap_gpio_irq_type() is handling it.

Note that the long term solution is to change the gpio-omap driver
to handle the banks as separate driver instances. This will allow
us to rely on just runtime PM for tracking the bank specific state.

Reported-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Javier Martinez Canillas <javier@dowhile0.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 26bc420b

drivers/gpio/gpio-omap.c

+33 −6
Original line number Diff line number Diff line
@@ -88,6 +88,8 @@ struct gpio_bank { 
#define BANK_USED(bank) (bank->mod_usage || bank->irq_usage)

#define LINE_USED(line, offset) (line & (BIT(offset)))



static void omap_gpio_unmask_irq(struct irq_data *d);



static int omap_irq_to_gpio(struct gpio_bank *bank, unsigned int gpio_irq)

{

	return bank->chip.base + gpio_irq;
@@ -477,6 +479,16 @@ static int omap_gpio_is_input(struct gpio_bank *bank, int mask) 
	return readl_relaxed(reg) & mask;

}



static void omap_gpio_init_irq(struct gpio_bank *bank, unsigned gpio,

			       unsigned offset)

{

	if (!LINE_USED(bank->mod_usage, offset)) {

		omap_enable_gpio_module(bank, offset);

		omap_set_gpio_direction(bank, offset, 1);

	}

	bank->irq_usage |= BIT(GPIO_INDEX(bank, gpio));

}



static int omap_gpio_irq_type(struct irq_data *d, unsigned type)

{

	struct gpio_bank *bank = omap_irq_data_get_bank(d);
@@ -506,15 +518,11 @@ static int omap_gpio_irq_type(struct irq_data *d, unsigned type) 
	spin_lock_irqsave(&bank->lock, flags);

	offset = GPIO_INDEX(bank, gpio);

	retval = omap_set_gpio_triggering(bank, offset, type);

	if (!LINE_USED(bank->mod_usage, offset)) {

		omap_enable_gpio_module(bank, offset);

		omap_set_gpio_direction(bank, offset, 1);

	} else if (!omap_gpio_is_input(bank, BIT(offset))) {

	omap_gpio_init_irq(bank, gpio, offset);

	if (!omap_gpio_is_input(bank, BIT(offset))) {

		spin_unlock_irqrestore(&bank->lock, flags);

		return -EINVAL;

	}



	bank->irq_usage |= BIT(GPIO_INDEX(bank, gpio));

	spin_unlock_irqrestore(&bank->lock, flags);



	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
@@ -792,6 +800,24 @@ static void omap_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) 
	pm_runtime_put(bank->dev);

}



static unsigned int omap_gpio_irq_startup(struct irq_data *d)

{

	struct gpio_bank *bank = omap_irq_data_get_bank(d);

	unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq);

	unsigned long flags;

	unsigned offset = GPIO_INDEX(bank, gpio);



	if (!BANK_USED(bank))

		pm_runtime_get_sync(bank->dev);



	spin_lock_irqsave(&bank->lock, flags);

	omap_gpio_init_irq(bank, gpio, offset);

	spin_unlock_irqrestore(&bank->lock, flags);

	omap_gpio_unmask_irq(d);



	return 0;

}



static void omap_gpio_irq_shutdown(struct irq_data *d)

{

	struct gpio_bank *bank = omap_irq_data_get_bank(d);
@@ -1181,6 +1207,7 @@ static int omap_gpio_probe(struct platform_device *pdev) 
	if (!irqc)

		return -ENOMEM;



	irqc->irq_startup = omap_gpio_irq_startup,

	irqc->irq_shutdown = omap_gpio_irq_shutdown,

	irqc->irq_ack = omap_gpio_ack_irq,

	irqc->irq_mask = omap_gpio_mask_irq,