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| author | Finn Thain <fthain@telegraphics.com.au> | 2018-12-01 11:53:10 +1100 |
|---|---|---|
| committer | Geert Uytterhoeven <geert@linux-m68k.org> | 2019-03-25 10:22:24 +0100 |
| commit | 1efdd4bd254311498123a15fa0acd565f454da97 (patch) | |
| tree | 6eed2d1e020561326c3754973e588c947673a5b0 /arch/m68k/q40/q40ints.c | |
| parent | 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b (diff) | |
| download | lwn-1efdd4bd254311498123a15fa0acd565f454da97.tar.gz lwn-1efdd4bd254311498123a15fa0acd565f454da97.zip | |
m68k: Call timer_interrupt() with interrupts disabled
Some platforms execute their timer handler with the interrupt priority
level set below 6. That means the handler could be interrupted by another
driver and this could lead to re-entry of the timer core.
Avoid this by use of local_irq_save/restore for timer interrupt dispatch.
This provides mutual exclusion around the timer interrupt flag access
which is needed later in this series for the clocksource conversion.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1811131407120.2697@nanos.tec.linutronix.de
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/q40/q40ints.c')
| -rw-r--r-- | arch/m68k/q40/q40ints.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/arch/m68k/q40/q40ints.c b/arch/m68k/q40/q40ints.c index 3e7603202977..1c696906c159 100644 --- a/arch/m68k/q40/q40ints.c +++ b/arch/m68k/q40/q40ints.c @@ -127,10 +127,10 @@ void q40_mksound(unsigned int hz, unsigned int ticks) sound_ticks = ticks << 1; } -static irq_handler_t q40_timer_routine; - -static irqreturn_t q40_timer_int (int irq, void * dev) +static irqreturn_t q40_timer_int(int irq, void *dev_id) { + irq_handler_t timer_routine = dev_id; + ql_ticks = ql_ticks ? 0 : 1; if (sound_ticks) { unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL; @@ -139,8 +139,13 @@ static irqreturn_t q40_timer_int (int irq, void * dev) *DAC_RIGHT=sval; } - if (!ql_ticks) - q40_timer_routine(irq, dev); + if (!ql_ticks) { + unsigned long flags; + + local_irq_save(flags); + timer_routine(0, NULL); + local_irq_restore(flags); + } return IRQ_HANDLED; } @@ -148,11 +153,9 @@ void q40_sched_init (irq_handler_t timer_routine) { int timer_irq; - q40_timer_routine = timer_routine; timer_irq = Q40_IRQ_FRAME; - if (request_irq(timer_irq, q40_timer_int, 0, - "timer", q40_timer_int)) + if (request_irq(timer_irq, q40_timer_int, 0, "timer", timer_routine)) panic("Couldn't register timer int"); master_outb(-1, FRAME_CLEAR_REG); |