Subject: [PATCH v2 2/3] ARM: OMAP4+: Move SRAM data to DT

From: [email-masked] (Santosh Shilimkar)
Date: Thu, 29 Aug 2013 09:51:50 -0400

On Thursday 29 August 2013 09:50 AM, Rajendra Nayak wrote:
> On Thursday 29 August 2013 07:01 PM, Santosh Shilimkar wrote:
>> On Thursday 29 August 2013 09:26 AM, Sekhar Nori wrote:
>>> On 8/29/2013 4:53 PM, Rajendra Nayak wrote:
>>>> diff --git a/arch/arm/boot/dts/omap4.dtsi b/arch/arm/boot/dts/omap4.dtsi
>>>> index 22d9f2b..1ba6a77 100644
>>>> --- a/arch/arm/boot/dts/omap4.dtsi
>>>> +++ b/arch/arm/boot/dts/omap4.dtsi
>>>> @@ -126,6 +126,11 @@
>>>>  			pinctrl-single,function-mask = <0x7fff>;
>>>>  		};
>>>>  
>>>> +		ocmcram: ocmcram at 40304000 {
>>>
>>> This can now be changed to 0x40300000 now that you have moved to
>>> gen_pool_alloc()?
>>>
>> NO.
>> It won't work on secure devices since first 16 KB is occupied for
>> default configuration. Its not worth trouble also to handle
>> secure/non-secure considering the use of SRAM which is actually just
>> limited to errata. 40304000 will work for both devices.
> 
> Right. Sekhar, you might have confused because of the existing buggy code
> in sram.c and sram.h which did this (and is removed in this series)
> 
> from sram.c
> -----------
>  #define OMAP2_SRAM_PUB_PA	(OMAP2_SRAM_PA + 0xf800)
>  #define OMAP3_SRAM_PUB_PA       (OMAP3_SRAM_PA + 0x8000)
> -#ifdef CONFIG_OMAP4_ERRATA_I688
> -#define OMAP4_SRAM_PUB_PA	OMAP4_SRAM_PA
> -#else
> -#define OMAP4_SRAM_PUB_PA	(OMAP4_SRAM_PA + 0x4000)
> -#endif
> -#define OMAP5_SRAM_PA		0x40300000
>  
> from sram.h
> -----------
>  #define OMAP2_SRAM_PA		0x40200000
>  #define OMAP3_SRAM_PA           0x40200000
> -#ifdef CONFIG_OMAP4_ERRATA_I688
> -#define OMAP4_SRAM_PA		0x40304000
> -#define OMAP4_SRAM_VA		0xfe404000
> -#else
> -#define OMAP4_SRAM_PA		0x40300000
> -#endif
> 
> I am not sure where the checks for CONFIG_OMAP4_ERRATA_I688
> came in from, but these are done, like Santosh said, to handle
> secure and non-secure sram across GP and HS devices and in
> no way related to handling errata I688.
> 
The check was to ensure that with errata enabled, we don't care
about first 16 KB ;-)