[U-Boot] [PATCH v3 1/8] da850: indicate cache usage disable in config file

[Ben Gardiner]

Hi,

On Wed, Aug 17, 2011 at 10:14 AM,  <nagabhushana.netagunte at ti.com> wrote:
> From: Nagabhushana Netagunte <nagabhushana.netagunte at ti.com>
>
> there are cache coherency issues when using the DAVINCI Ethernet driver,
> hence caches cant be used for da850 u-boot. As per new cache management
> framework,if the caches are not used in u-boot, it needs to be explicitly
> indicated through macros in config file. CACHE disable is  indicated by
> the following macro definitions in config file,
>
> 1. CONFIG_SYS_ICACHE_OFF
> 2. CONFIG_SYS_DCACHE_OFF
> 3. CONFIG_SYS_L2CACHE_OFF
>
> Signed-off-by: Nagabhushana Netagunte <nagabhushana.netagunte at ti.com>
> ---
>  include/configs/da850evm.h |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/include/configs/da850evm.h b/include/configs/da850evm.h
> index bbb5a9b..fdcc6e3 100644
> --- a/include/configs/da850evm.h
> +++ b/include/configs/da850evm.h
> @@ -42,6 +42,9 @@
>  #define CONFIG_SYS_HZ                  1000
>  #define CONFIG_SKIP_LOWLEVEL_INIT
>  #define CONFIG_SYS_TEXT_BASE           0xc1080000
> +#define CONFIG_SYS_ICACHE_OFF
> +#define CONFIG_SYS_DCACHE_OFF
> +#define CONFIG_SYS_L2CACHE_OFF

I've done plenty of tftp transfers of rootfs and kernel images and
flashed these to the da850evm with the caches enabled and I can't say
I've ever encountered a fatal issue here.

I understand that both Laurence and Stefan (cc'd) have confirmed that
there dcache issues with the EMA; I am assuming that the 'issue'
results in a delay in tftp'ing...

Disabling the caches will slow down decompression which will slow down
boot overall when booting from flash.

Rather than masking the issue by disabling caches and slowing down
u-boot for it's users perhaps TI should be fixing the EMAC drivers'
cache bugs instead?

Best Regards,
Ben Gardiner

---
Nanometrics Inc.
http://www.nanometrics.ca