-----Original Message-----
From: ext Catalin Marinas [mailto:catalin.marinas at arm.com] 
Sent: 24 November, 2009 15:20
To: Russell King - ARM Linux
Cc: Kristo Tero (Nokia-D/Tampere); linux-omap at vger.kernel.org; 
linux-arm-kernel at lists.infradead.org; Dave Estes
Subject: Re: [PATCH 1/2] ARM: Implemented support for VFP PM 
context saving

On Tue, 2009-11-24 at 11:48 +0000, Russell King - ARM Linux wrote:

quoted

On Tue, Nov 24, 2009 at 12:37:03PM +0200, Tero Kristo wrote:

quoted

In some ARM architectures, like OMAP3, the VFP context can 

be lost during

quoted

quoted

dynamic sleep cycle. For this purpose, there is now a function
vfp_pm_save_context() that should be called before the VFP 

is assumed to

quoted

quoted

lose context. Next VFP trap will then restore context 

automatically.

quoted

quoted

We need to have the last_VFP_context[cpu] cleared after 

the save in idle,

quoted

quoted

else the restore would fail to restore when it sees that 

the last_VFP_context

quoted

quoted

is same as the current threads vfp_state. This happens 

when the same

quoted

quoted

process/thread traps an exception post idle.

Main work for this patch was done by Peter and Rajendra. 

Some cleanup and

quoted

quoted

optimization by Tero.

Why not re-use vfp_pm_suspend() ?  Haven't you shown that 

vfp_pm_suspend

quoted

may be buggy since it doesn't save in the VFP-disabled case?

BTW, the two patches below were mentioned to me some time ago but I
haven't got the time to look at them:

[ARM] vfp: Fix bug in vfp_pm_suspend
https://www.codeaurora.org/gitweb/quic/le/?p=kernel/msm.git;a=c
ommit;h=88984c9b2d69c222ee1e2afc948ca73f597d40ff

[ARM] vfp: Add additional vfp interfaces
https://www.codeaurora.org/gitweb/quic/le/?p=kernel/msm.git;a=c
ommit;h=393e4bfaaf79377d29cd6bb2228f87601aeca668

These look pretty much like the same thing we have attempted on the omap3 patches, I could try these out and check if they work for omap3 also. They fix the potentially broken suspend also.

-Tero