ARM: OMAP3: Warn about spurious interrupts

In the case of spurious interrupt, the handler for previous interrupt
handler needs to flush posted writes with a read back of the interrupt
ack register. Warn about handlers that need to flush posted writes.

Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Tony Lindgren 2008-12-10 17:36:52 -08:00
parent 64ce2907b1
commit 6ccc4c0ded

View File

@ -23,6 +23,7 @@
#define INTC_REVISION 0x0000
#define INTC_SYSCONFIG 0x0010
#define INTC_SYSSTATUS 0x0014
#define INTC_SIR 0x0040
#define INTC_CONTROL 0x0048
#define INTC_MIR_CLEAR0 0x0088
#define INTC_MIR_SET0 0x008c
@ -60,6 +61,30 @@ static u32 intc_bank_read_reg(struct omap_irq_bank *bank, u16 reg)
return __raw_readl(bank->base_reg + reg);
}
static int previous_irq;
/*
* On 34xx we can get occasional spurious interrupts if the ack from
* an interrupt handler does not get posted before we unmask. Warn about
* the interrupt handlers that need to flush posted writes.
*/
static int omap_check_spurious(unsigned int irq)
{
u32 sir, spurious;
sir = intc_bank_read_reg(&irq_banks[0], INTC_SIR);
spurious = sir >> 6;
if (spurious > 1) {
printk(KERN_WARNING "Spurious irq %i: 0x%08x, please flush "
"posted write for irq %i\n",
irq, sir, previous_irq);
return spurious;
}
return 0;
}
/* XXX: FIQ and additional INTC support (only MPU at the moment) */
static void omap_ack_irq(unsigned int irq)
{
@ -70,6 +95,20 @@ static void omap_mask_irq(unsigned int irq)
{
int offset = irq & (~(IRQ_BITS_PER_REG - 1));
if (cpu_is_omap34xx()) {
int spurious = 0;
/*
* INT_34XX_GPT12_IRQ is also the spurious irq. Maybe because
* it is the highest irq number?
*/
if (irq == INT_34XX_GPT12_IRQ)
spurious = omap_check_spurious(irq);
if (!spurious)
previous_irq = irq;
}
irq &= (IRQ_BITS_PER_REG - 1);
intc_bank_write_reg(1 << irq, &irq_banks[0], INTC_MIR_SET0 + offset);