[PATCH 3/4] pm: Handle HID0_SLEEP in the TLF_NAPPING hack.
From: Scott Wood <hidden>
Date: 2007-07-12 19:13:09
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The e300 core (and probably most other 6xx chips) can only come out of sleep mode with an interrupt. However, interrupts are logically disabled by the power management layer. This hack extends the existing doze/nap hack to also suppress the running of the interrupt handler when in sleep mode. Signed-off-by: Scott Wood <redacted> --- arch/powerpc/kernel/idle_6xx.S | 34 +++++++++++++++++++++++++++++++++- 1 files changed, 33 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 01bcd52..f45d634 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S@@ -147,6 +147,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) isync b 1b +#ifdef CONFIG_PM +ret_from_sleep: + .long ret_from_except + .long ret_from_except +#endif + /* * Return from NAP/DOZE mode, restore some CPU specific registers, * we are called with DR/IR still off and r2 containing physical
@@ -154,7 +160,33 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) * address). We have to preserve r10. */ _GLOBAL(power_save_6xx_restore) - lwz r9,_LINK(r11) /* interrupted in ppc6xx_idle: */ +#ifdef CONFIG_PM + mfspr r9, SPRN_HID0 + andis. r9, r9, HID0_SLEEP@h + beq+ 1f + + /* + * SLEEP mode is invoked through the PM subsystem, which means + * that interrupts should be disabled. However, the hardware + * requires them to be enabled to wake up. To prevent the + * interrupt from being visible to Linux, return immediately + * rather than run the interrupt handler. + */ + lis r9, ret_from_sleep@h + ori r9, r9, ret_from_sleep@l + tophys(r9, r9) + mtlr r9 + + /* + * Disable interrupts, so that the interrupt doesn't happen + * again until the PM code sets MSR[EE]. + */ + lwz r9, _MSR(r11) + rlwinm r9, r9, 0, ~MSR_EE + stw r9, _MSR(r11) +#endif + +1: lwz r9,_LINK(r11) /* interrupted in ppc6xx_idle: */ stw r9,_NIP(r11) /* make it do a blr */ #ifdef CONFIG_SMP
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1.5.0.3