Josh Boyer wrote:

On Thu, 20 Sep 2007 12:32:56 -0500 (CDT)
Milton Miller [off-list ref] wrote:

quoted

On Fri Sep 21 02:56:32 EST 2007, Valentine Barshak wrote:

quoted

Josh Boyer wrote:

quoted

On Wed, 19 Sep 2007 14:30:24 -0500
Olof Johansson <olof at lixom.net> wrote:

quoted

On Wed, Sep 19, 2007 at 09:19:47PM +0200, Stefan Roese wrote:

quoted

Hi Valentine,

On Wednesday 19 September 2007, Valentine Barshak wrote:

quoted

Disabling write pipelining really helps.
Josh, David, what is the right place to put this workaround to?

Is it OK to do mtdcr(PLB4A0_ACR, mfdcr(PLB4A0_ACR) & ~PLB4_WRP); in
arch/powerpc/boot/cuboot-sequoia.c:sequoia_fixups()?
or
should this be done in
arch/powerpc/platforms/44x/sequoia.c:sequoia_setup_arch()
with dcr_map, dcr_read/write stuff?

I vote for putting it into sequoia.c, since it's very likely to happen that 
Sequoia will at one point be booted without the bootwrapper. Or perhaps it 
should go into some common code checking the PVR and disabling it when this 
440EPx/GRx is detected, since all those boards are affected.

This is what we have setup_cpu functions in the cpu table for. Please
put it there instead of in board code.

Yes, agreed.

I was thinking about it. Looks like it's the best place, but the code 
that actually calls setup_cpu is under ifdef CONFIG_PPC64, while lots of 
cpu_setup functions are defined for ppc32 processors.
Is it OK to remove this ifdef, or should I do CONFIG_PPC64 || CONFIG_44x?

head_32.S calls call_setup_cpu in misc_32.S to call the cpu setup functon.

Note that these functions are called before the kernel is copied down to
0, so on ppc32 you will need the PTRRELOC type stuff.  Also the callsite
implies that the cpu number is available in r24, which may or may not be
true when called from C.

Its probably easier to just call call_setup_cpu in the other 32 bit 
head_xxx files.

Hm.  I'll have to see how well that would work for 4xx.  Seems 8xx and
FSL BookE are in a similar situation.

I started preparing the patch after Olof's "take out the ifdef" :)
I've tested it on 4xx. seems to work fine. FPU works OK and EPX/GRX 
workaround is fine also, but it has to be tested on 8xx and fsl.
Adding call_setup_cpu to head_44x is no problem.

josh