[U-Boot] [PATCH] ppc: Unlock cache-as-ram in a consistent manner

[Kim Phillips]

On Fri, 24 Jul 2009 15:46:16 +0200
Wolfgang Denk <wd at denx.de> wrote:

> Dear Peter,
> 
> In message <20090723190101.C8F8A832E416 at gemini.denx.de> I wrote:
> >
> > In message <1247269570-11406-1-git-send-email-ptyser at xes-inc.com> you wrote:
> > > Previously, non-e500 architectures only unlocked their data cache which
> > > was used as early RAM when booting to Linux using the "bootm" command.
> > > This change causes all PPC boards with CONFIG_SYS_INIT_RAM_LOCK defined
> > > to unlock their data cache during U-Boot's initialization.  This
> > > improves U-Boot performance and provides a common cache state when
> > > booting to different OSes.
> ...
> > Hm... tested on TQM834x - it's still booting, but flash recognition
> > stopped working:
> 
> I git-bisected the problem on TQM834x:
> 
> 982adfc610669482a32127282fe489857a92cfe3 is first bad commit
> commit 982adfc610669482a32127282fe489857a92cfe3
> Author: Peter Tyser <ptyser at xes-inc.com>
> Date:   Fri Jul 10 18:46:10 2009 -0500
> 
>     ppc: Unlock cache-as-ram in a consistent manner
>     
>     Previously, non-e500 architectures only unlocked their data cache which
>     was used as early RAM when booting to Linux using the "bootm" command.
>     This change causes all PPC boards with CONFIG_SYS_INIT_RAM_LOCK defined
>     to unlock their data cache during U-Boot's initialization.  This
>     improves U-Boot performance and provides a common cache state when
>     booting to different OSes.
>     
>     Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
> 
> :040000 040000 bf1093b8403580234125df8e97d948c318e8965f 5dce3a5e28ea46706aba44ec62e88584883d0cc4 M   lib_ppc
> 
> 
> Please suggest how to continue. Shall I revert this commit?

with this patch, this mpc8313 board does this:

U-Boot 2009.06-00524-g28958b8 (Jul 23 2009 - 18:33:11) MPC83XX

Reset Status:

CPU:   e300c3, MPC8313E, Rev: 1.0 at 333.333 MHz, CSB: 166.667 MHz
Board: Freescale MPC8313ERDB
I2C:   ready
DRAM:  128 MB
FLASH: ## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB
*** failed ***
### ERROR ### Please RESET the board ###

and when reverted, it boots normally, so the board wants to agree that
this patch is reverted.

Kim