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| author |   Russell King <rmk@dyn-67.arm.linux.org.uk> | 2006-06-08 17:59:31 +0100 |
|---|---|---|
| committer |   Russell King <rmk+kernel@arm.linux.org.uk> | 2006-06-08 17:59:31 +0100 |
| commit | d782f33df706f1b8a4496b41fd7d339c6e23aa59 (patch) | |
| tree | ab3241bfff98d3114f5f1337ca3885720f396276 /arch | |
| parent | Linux 2.6.17-rc6 (diff) | |
| download | linux-dev-d782f33df706f1b8a4496b41fd7d339c6e23aa59.tar.xz linux-dev-d782f33df706f1b8a4496b41fd7d339c6e23aa59.zip | |
[ARM] Fix Neponset IRQ handling
While testing the genirq code on ARM, a condition was found whereby
the Neponset IRQ handler was being re-entered, causing the system
to deadlock.
Under the ARM IRQ code, this would not have been a visible problem
because the "simple" IRQ handling had no re-entrancy protection.
Resolve this by acknowledging the parent interrupt after we mask it
when we are going to handle one of our "special" level-based sources
(from ethernet or USAR chip.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mach-sa1100/neponset.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/mach-sa1100/neponset.c b/arch/arm/mach-sa1100/neponset.c index 9e02bc3712a0..af6d2775cf82 100644 --- a/arch/arm/mach-sa1100/neponset.c +++ b/arch/arm/mach-sa1100/neponset.c @@ -59,6 +59,14 @@ neponset_irq_handler(unsigned int irq, struct irqdesc *desc, struct pt_regs *reg if (irr & (IRR_ETHERNET | IRR_USAR)) { desc->chip->mask(irq); + /* + * Ack the interrupt now to prevent re-entering + * this neponset handler. Again, this is safe + * since we'll check the IRR register prior to + * leaving. + */ + desc->chip->ack(irq); + if (irr & IRR_ETHERNET) { d = irq_desc + IRQ_NEPONSET_SMC9196; desc_handle_irq(IRQ_NEPONSET_SMC9196, d, regs); |