[PATCH] OMAP2: PM: fix fault in enter_full_retention()

[PATCH] OMAP2: PM: fix fault in enter_full_retention()

[Kevin Hilman]

In omap24xx_cpu_suspend assembly routine, the r2 register which holds
the address of the SDRC_POWER reg is set to zero before the value is
written back triggering a fault due to writing to address zero.

It's hard to tell where this change was introduced since this file
has been moved and merged.

While this fix prevents a crash, suspend on my n810 is broken with
current kernels.  I never come out of suspend.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/mach-omap2/sleep24xx.S |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/sleep24xx.S b/arch/arm/mach-omap2/sleep24xx.S
index 43336b9..bf9e961 100644
--- a/arch/arm/mach-omap2/sleep24xx.S
+++ b/arch/arm/mach-omap2/sleep24xx.S
@@ -93,9 +93,8 @@ ENTRY(omap24xx_cpu_suspend)
 	orr	r4, r4, #0x40		@ enable self refresh on idle req
 	mov	r5, #0x2000		@ set delay (DPLL relock + DLL relock)
 	str	r4, [r2]		@ make it so
-	mov	r2, #0
 	nop
-	mcr	p15, 0, r2, c7, c0, 4	@ wait for interrupt
+	mcr	p15, 0, r3, c7, c0, 4	@ wait for interrupt
 	nop
 loop:
 	subs	r5, r5, #0x1		@ awake, wait just a bit
-- 
1.6.0.3

Re: [PATCH] OMAP2: PM: fix fault in enter_full_retention()

[Tony Lindgren]

* Kevin Hilman <khilman@deeprootsystems.com> [081205 23:55]:
> In omap24xx_cpu_suspend assembly routine, the r2 register which holds
> the address of the SDRC_POWER reg is set to zero before the value is
> written back triggering a fault due to writing to address zero.
> 
> It's hard to tell where this change was introduced since this file
> has been moved and merged.

Pushing to l-o tree, and adding to omap-fixes queue for mainline.

> While this fix prevents a crash, suspend on my n810 is broken with
> current kernels.  I never come out of suspend.

Bummer.

Tony

> 
> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
> ---
>  arch/arm/mach-omap2/sleep24xx.S |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/sleep24xx.S b/arch/arm/mach-omap2/sleep24xx.S
> index 43336b9..bf9e961 100644
> --- a/arch/arm/mach-omap2/sleep24xx.S
> +++ b/arch/arm/mach-omap2/sleep24xx.S
> @@ -93,9 +93,8 @@ ENTRY(omap24xx_cpu_suspend)
>  	orr	r4, r4, #0x40		@ enable self refresh on idle req
>  	mov	r5, #0x2000		@ set delay (DPLL relock + DLL relock)
>  	str	r4, [r2]		@ make it so
> -	mov	r2, #0
>  	nop
> -	mcr	p15, 0, r2, c7, c0, 4	@ wait for interrupt
> +	mcr	p15, 0, r3, c7, c0, 4	@ wait for interrupt
>  	nop
>  loop:
>  	subs	r5, r5, #0x1		@ awake, wait just a bit
> -- 
> 1.6.0.3
> 
> --
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