Re: FW: Alchemy power managment code.

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Nico Coesel wrote:

> Ralf,
> Funny you ask because I tried this yesterday on a AU1100 system with the
> 2.6.24 kernel (from kernel.org). I'm afraid I must say the kernel
> crashes when I enable power management. The reason I want to use power
> management is because I need to send the CPU to sleep when the system
> shuts down. I hacked power.c and reset.c a bit so au_sleep() is called
> when the system is shut down. Perhaps someone can confirm the
> powermanagement can be made to work with some fixes (it didn't work with
> 2.6.21-rc4 either).

    BTW, if you look at sleeper.S you'll find that save_and_sleep() trashes 
registers $1 and $2 because of reusing their stackframe slots to save Status 
and Context CP0 registers:

         sw      $1, PT_R1(sp)
         sw      $2, PT_R2(sp)

         mfc0    k0, CP0_STATUS
         sw      k0, 0x20(sp)		# equals PT_R2
         mfc0    k0, CP0_CONTEXT
         sw      k0, 0x1c(sp)		# equals PT_R1

> Nico Coesel 

WBR, Sergei