Re: [PATCH v2] ARM: mach-shmobile: sh7372 A4R suspend/resume order fix

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Wednesday, November 09, 2011, Guennadi Liakhovetski wrote:
> Update the sh7372 A4R code to make sure the suspend
> callback gets to be called before the resume callback.
> 
> Without this fix the A4R resume callback is called before
> suspend. The resume callback restores the INTCS hardware
> registers with incorrect data which results in interrupts
> being masked when they shouldn't be. The user will notice
> this issue as IIC0 timing out during boot.
> 
> Thanks to Magnus Damm for tracking this problem down and providing the 
> initial fix and the commit description text.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
> 
> I took the liberty to reimplement the original fix by Magnus in a 
> different way. I didn't quite like the idea of rewriting platform data, 
> which could and, probably, should actually be const, on each 
> domain-suspend. Instead, checking in resume, whether a valid state 
> snapshot is available seemed a bit prettier to me:-) The maintainer is, of 
> course, free to choose whichever version he prefers, they both
> 
> "Fix issue in v3.2-rc1 on the sh7372 Mackerel board."

Magnus, Paul, which one do you want me to take?

Rafael


> diff --git a/arch/arm/mach-shmobile/intc-sh7372.c b/arch/arm/mach-shmobile/intc-sh7372.c
> index 29cdc05..eeeb16b 100644
> --- a/arch/arm/mach-shmobile/intc-sh7372.c
> +++ b/arch/arm/mach-shmobile/intc-sh7372.c
> @@ -627,6 +627,7 @@ void __init sh7372_init_irq(void)
>  
>  static unsigned short ffd2[0x200];
>  static unsigned short ffd5[0x100];
> +static bool intcs_state_saved = false;
>  
>  void sh7372_intcs_suspend(void)
>  {
> @@ -646,12 +647,17 @@ void sh7372_intcs_suspend(void)
>  
>  	for (k = 0x80; k <= 0x9c; k += 4)
>  		ffd5[k] = __raw_readb(intcs_ffd5 + k);
> +
> +	intcs_state_saved = true;
>  }
>  
>  void sh7372_intcs_resume(void)
>  {
>  	int k;
>  
> +	if (!intcs_state_saved)
> +		return;
> +
>  	for (k = 0x00; k <= 0x30; k += 4)
>  		__raw_writew(ffd2[k], intcs_ffd2 + k);
>  
> 
>