Commit 2466211e authored by Tero Kristo's avatar Tero Kristo Committed by Kevin Hilman
Browse files

OMAP3: Fixed crash bug with serial + suspend 



It was possible for an unhandled interrupt to occur if there was incoming
serial traffic during wakeup from suspend. This was caused by the code
in arch-arm/mach-omap2/serial.c keeping interrupt enabled all the time,
but not acking its interrupts. Applies on top of PM branch.

Use the PM begin/end hooks to ensure that the "serial idle" interrupts
are disabled during the suspend path.  Also, since begin/end hooks are
now used, use the suspend_state that is passed in the begin hook instead
of the enter hook as per the platform_suspend_ops docs.

Signed-off-by: default avatarTero Kristo <tero.kristo@nokia.com>
Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
parent 4789998a

arch/arm/mach-omap2/pm34xx.c

+21 −2
Original line number Diff line number Diff line
@@ -296,6 +296,8 @@ out: 
}



#ifdef CONFIG_SUSPEND

static suspend_state_t suspend_state;



static int omap3_pm_prepare(void)

{

	disable_hlt();
@@ -342,11 +344,11 @@ restore: 
	return ret;

}



static int omap3_pm_enter(suspend_state_t state)

static int omap3_pm_enter(suspend_state_t unused)

{

	int ret = 0;



	switch (state) {

	switch (suspend_state) {

	case PM_SUSPEND_STANDBY:

	case PM_SUSPEND_MEM:

		ret = omap3_pm_suspend();
@@ -363,7 +365,24 @@ static void omap3_pm_finish(void) 
	enable_hlt();

}



/* Hooks to enable / disable UART interrupts during suspend */

static int omap3_pm_begin(suspend_state_t state)

{

	suspend_state = state;

	omap_uart_enable_irqs(0);

	return 0;

}



static void omap3_pm_end(void)

{

	suspend_state = PM_SUSPEND_ON;

	omap_uart_enable_irqs(1);

	return;

}



static struct platform_suspend_ops omap_pm_ops = {

	.begin		= omap3_pm_begin,

	.end		= omap3_pm_end,

	.prepare	= omap3_pm_prepare,

	.enter		= omap3_pm_enter,

	.finish		= omap3_pm_finish,

arch/arm/mach-omap2/serial.c

+14 −0
Original line number Diff line number Diff line
@@ -435,6 +435,20 @@ static void omap_uart_idle_init(struct omap_uart_state *uart) 
	WARN_ON(ret);

}



void omap_uart_enable_irqs(int enable)

{

	int ret;

	struct omap_uart_state *uart;



	list_for_each_entry(uart, &uart_list, node) {

		if (enable)

			ret = request_irq(uart->p->irq, omap_uart_interrupt,

				IRQF_SHARED, "serial idle", (void *)uart);

		else

			free_irq(uart->p->irq, (void *)uart);

	}

}



static ssize_t sleep_timeout_show(struct kobject *kobj,

				  struct kobj_attribute *attr,

				  char *buf)

arch/arm/plat-omap/include/mach/serial.h

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ extern void omap_uart_check_wakeup(void); 
extern void omap_uart_prepare_suspend(void);

extern void omap_uart_prepare_idle(int num);

extern void omap_uart_resume_idle(int num);

extern void omap_uart_enable_irqs(int enable);

#endif



#endif

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