Subject: [PATCH] ARM: OMAP4: sleep: Save the complete used register stack frame

From: [email-masked] (Kevin Hilman)
Date: Wed, 08 Aug 2012 10:15:20 -0700

Santosh Shilimkar <[email-masked]> writes:

> OMAP4 sleep entry code even though itself don't use many CPU registers
> makes call to the v7_flush_dcache_all() which uses them. Since
> v7_flush_dcache_all() doesn't make use of stack, the caller must take
> care of the stack frame. Otherwise it will lead to corrupted stack frame.
>
> Fix it by saving used registers.
>
> Reported-by: Grygorii Strashko <[email-masked]>
> Signed-off-by: Santosh Shilimkar <[email-masked]>
> Cc: Kevin Hilman <[email-masked]>

Please add a brief comment in the code as well explaining why the
additional registers are saved/restored.

After that, I'll add to my PM fixes queue for v3.6-rc.

Thanks for the fix.

Kevin

> ---
>  arch/arm/mach-omap2/sleep44xx.S |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
> index 9f6b83d..b5823e9 100644
> --- a/arch/arm/mach-omap2/sleep44xx.S
> +++ b/arch/arm/mach-omap2/sleep44xx.S
> @@ -58,7 +58,7 @@ ppa_por_params:
>   * CPU failed to transition to targeted OFF/DORMANT state.
>   */
>  ENTRY(omap4_finish_suspend)
> -	stmfd	sp!, {lr}
> +	stmfd	sp!, {r4-r12, lr}
>  	cmp	r0, #0x0
>  	beq	do_WFI				@ No lowpower state, jump to WFI
>  
> @@ -226,7 +226,7 @@ scu_gp_clear:
>  skip_scu_gp_clear:
>  	isb
>  	dsb
> -	ldmfd	sp!, {pc}
> +	ldmfd	sp!, {r4-r12, pc}
>  ENDPROC(omap4_finish_suspend)
>  
>  /*