From: David Daney <david.da...@cavium.com>
As noted by Thomas Gleixner:
commit cdbedc61c8 (mips: Use generic idle loop) broke MIPS as I did
not realize that MIPS wants to invoke the wait instructions with
interrupts enabled.
Instead of enabling interrupts in arch_cpu_idle() as Thomas' initial
patch does, we follow Linus' suggestion of doing it in the assembly
code to prevent the compiler from rearranging things.
Signed-off-by: David Daney <david.da...@cavium.com>
Reported-by: EunBong Song <eunb.s...@samsung.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Jonas Gorski <j...@openwrt.org>
---
This is only very lightly tested, we need more testing before
declaring it the definitive fix.
arch/mips/kernel/genex.S | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index ecb347c..57cda9a 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -132,12 +132,13 @@ LEAF(r4k_wait)
.set noreorder
/* start of rollback region */
LONG_L t0, TI_FLAGS($28)
- nop
andi t0, _TIF_NEED_RESCHED
bnez t0, 1f
nop
- nop
- nop
+ /* Enable interrupts so WAIT will complete */
+ mfc0 t0, CP0_STATUS
+ ori t0, ST0_IE
+ mtc0 t0, CP0_STATUS
.set mips3
wait
/* end of rollback region (the region size must be power of two) */
--
1.7.11.7
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