On Fri, Jun 24, 2011 at 10:37:50AM +0100, Russell King - ARM Linux wrote:
> On Fri, Jun 24, 2011 at 04:42:26PM +0900, Kukjin Kim wrote:
> > Russell King - ARM Linux wrote:
> >
> > > Stop bodging stuff (like you have for the SCU stuff.) and start _talking_
> > > to people if the code doesn't do what you need it to do.
> >
> > Hi Russell and all,
> >
> > I'd like to share requirement of EXYNOS4210 PM.
> >
> > Now if there is wakeup source which is pending before entering suspend mode,
> > PMU(Power Management Unit) handles WFI instruction as NOP on EXYNOS4210. But
> > it seems that current cpu_suspend() cannot support this. So how can/should
> > we handle this case?
>
> See patch from June 13th posted to the hibernate thread. This allows
> the finisher function to return, though it should only return if it is
> certain that the system will not enter suspend.
>
> Is this true of the current exynos4 code? It seems that the current
> code will panic() if the WFI is executed as a NOP.
Here's an updated patch for it against the v3 set of patches.
arch/arm/include/asm/suspend.h | 9 +++++----
arch/arm/kernel/sleep.S | 11 +++++++++--
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h
index f8db9d0..54821b5 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -10,12 +10,13 @@ extern void cpu_resume(void);
* Hide the first two arguments to __cpu_suspend - these are an implementation
* detail which platform code shouldn't have to know about.
*/
-static inline void cpu_suspend(unsigned long arg, void (*fn)(unsigned long))
+static inline int cpu_suspend(unsigned long arg, void (*fn)(unsigned long))
{
- extern void __cpu_suspend(int, long, unsigned long,
- void (*)(unsigned long));
- __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn);
+ extern int __cpu_suspend(int, long, unsigned long,
+ void (*)(unsigned long));
+ int ret = __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn);
flush_tlb_all();
+ return ret;
}
#endif
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index c156d0e..dc902f2 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -12,7 +12,6 @@
* r1 = v:p offset
* r2 = suspend function arg0
* r3 = suspend function
- * Note: does not return until system resumes
*/
ENTRY(__cpu_suspend)
stmfd sp!, {r4 - r11, lr}
@@ -26,7 +25,7 @@ ENTRY(__cpu_suspend)
#endif
mov r6, sp @ current virtual SP
sub sp, sp, r5 @ allocate CPU state on stack
- mov r0, sp @ save pointer
+ mov r0, sp @ save pointer to CPU save block
add ip, ip, r1 @ convert resume fn to phys
stmfd sp!, {r1, r6, ip} @ save v:p, virt SP, phys resume fn
ldr r5, =sleep_save_sp
@@ -55,10 +54,17 @@ ENTRY(__cpu_suspend)
#else
bl __cpuc_flush_kern_all
#endif
+ adr lr, BSYM(cpu_suspend_abort)
ldmfd sp!, {r0, pc} @ call suspend fn
ENDPROC(__cpu_suspend)
.ltorg
+cpu_suspend_abort:
+ ldmia sp!, {r1 - r3} @ pop v:p, virt SP, phys resume fn
+ mov sp, r2
+ ldmfd sp!, {r4 - r11, pc}
+ENDPROC(cpu_suspend_abort)
+
/*
* r0 = control register value
* r1 = v:p offset (preserved by cpu_do_resume)
@@ -89,6 +95,7 @@ cpu_resume_after_mmu:
str r5, [r2, r4, lsl #2] @ restore old mapping
mcr p15, 0, r0, c1, c0, 0 @ turn on D-cache
bl cpu_init @ restore the und/abt/irq banked regs
+ mov r0, #0 @ return zero on success
ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_resume_after_mmu)
--
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