Re: [PATCH 9/10] Vmi timer update.patch

[Zachary Amsden]

Chris Wright wrote:
> * Zachary Amsden (zach@xxxxxxxxxx) wrote:
>   
> > Yes, but unfortunately that is a nop:
> >
> >         /*
> >          * Avoid unnecessary state transitions, as it confuses
> >          * Geode / Cyrix based boxen.
> >          */
> >         case CLOCK_EVT_MODE_SHUTDOWN:
> >                 if (evt->mode == CLOCK_EVT_MODE_UNUSED)
> >                         break;
> >         case CLOCK_EVT_MODE_UNUSED:
> >                 if (evt->mode == CLOCK_EVT_MODE_SHUTDOWN)
> >                         break;
> >     
>
> This one should be fallthrough case during exchange (mode == PERIODIC)
>   

Yes, seems PERIODIC->SHUTDOWN should do the right thing.


> >         case CLOCK_EVT_MODE_ONESHOT:
> >                 /* One shot setup */
> >                 outb_p(0x38, PIT_MODE);
> >
> > So switching from PIT to VMI does not disable PIT timer interrupts.  
> > Thus I have to keep this part of the patch.
> >     

Since I misread the code, I can drop this now.


> Oh, I was looking at this (x86_64 work I have here):
>
> 	case CLOCK_EVT_MODE_SHUTDOWN:
> 	case CLOCK_EVT_MODE_UNUSED:
> 		outb_p(0x30, PIT_MODE);
> 		outb_p(0, PIT_CH0);	/* LSB */
> 		outb_p(0, PIT_CH0);	/* MSB */
> 		break;
>
> That's mode 0, not mode 5, but I think the end result is the same.
>   

Yes, mode 0, 4, 5 all should behave similarly.

Zach
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