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gpio: omap: Fix bad device access with setup_irq()

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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: Russell 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: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Tony Lindgren 2015-01-16 14:50:50 -08:00 committed by Linus Walleij
parent 26bc420b59
commit 3d009c8c61
1 changed files with 33 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/gpio/gpio-omap.c
View File

@ -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 @@ exit:
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,