From 010c108d7af708d9e09b83724a058a76803fbc66 Mon Sep 17 00:00:00 2001 From: David VomLehn Date: Mon, 21 Dec 2009 17:49:22 -0800 Subject: MIPS: PowerTV: Fix support for timer interrupts with > 64 external IRQs The MIPS processor is limited to 64 external interrupt sources. Using a greater number without IRQ sharing requires reading platform-specific registers. On such platforms, reading the IntCtl register to determine which interrupt corresponds to a timer interrupt will not work. On MIPSR2 systems there is a solution - the TI bit in the Cause register, specifically indicates that a timer interrupt has occured. This patch uses that bit to detect interrupts for MIPSR2 processors, which may be expected to work regardless of how the timer interrupt may be routed in the hardware. Signed-off-by: David VomLehn (dvomlehn@cisco.com) To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/804/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/cevt-r4k.c | 2 +- arch/mips/kernel/traps.c | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c index b469ad05d520..0b2450ceb13f 100644 --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c @@ -97,7 +97,7 @@ void mips_event_handler(struct clock_event_device *dev) */ static int c0_compare_int_pending(void) { - return (read_c0_cause() >> cp0_compare_irq) & 0x100; + return (read_c0_cause() >> cp0_compare_irq_shift) & (1ul << CAUSEB_IP); } /* diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 308e43460864..338dfe8ed002 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1403,6 +1403,7 @@ extern void flush_tlb_handlers(void); * Timer interrupt */ int cp0_compare_irq; +int cp0_compare_irq_shift; /* * Performance counter IRQ or -1 if shared with timer @@ -1493,8 +1494,9 @@ void __cpuinit per_cpu_trap_init(void) * o read IntCtl.IPPCI to determine the performance counter interrupt */ if (cpu_has_mips_r2) { - cp0_compare_irq = (read_c0_intctl() >> 29) & 7; - cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7; + cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP; + cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7; + cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7; if (cp0_perfcount_irq == cp0_compare_irq) cp0_perfcount_irq = -1; } else { -- cgit v1.2.3