Re: AMD 768 erratum 10 (solved: AMD 760MPX DMA lockup)

[Maxwell Spangler <maxwax@speakeasy.net>]

Does this mouse have to be actively used...

Could one plug a cheap ps/2 mouse into that port and yet continue to use a USB 
mouse if X is configured to use it?

What is actually happening that causes the ps/2 mouse to cure this or any 
other problem of this nature?

Curious.

On Fri, 27 Sep 2002, Jan Kasprzak wrote:

> Manfred Spraul wrote:
> : The errata is not PS/2 mouse specific:
> : it says that the io apic doesn't implement masking interrupts correctly.
> 
> 	Yes, but it says that problem has not been observed when running
> with PS/2 mouse. Which is exactly what I observe on my system.
> : 
> : Linux uses masking aggressively - disable_irq() is implemented by 
> : masking the interrupt in the io apic. I'm surprised that this doesn't 
> : cause frequent problems.
> 
> 	The errata does not say that the interrupt masking in the IO-APIC
> does not work in all situations. I read it as the lock-up (caused by
> nonfunctional IRQ masking) sometimes occurs, nobody knows when,
> and it has been observed on some Netware boxes w/o the PS/2 mouse.
> Maybe even AMD does not know exactly what is going on there.
> 
> : Regarding Jan's problem: I'm not sure if his problems are related to 
> : this errata. It says that using a PS/2 mouse instead of a serial mouse 
> : with Novell Netward avoids the hang during shutdown, probably because 
> : then netware doesn't mask the irq.
> 
> 	Yes, it may be a faulty board as well, but I think it is
> too close to this AMD errata.
> 
> -Yenya
> 
> -- 
> | Jan "Yenya" Kasprzak  <kas at {fi.muni.cz - work | yenya.net - private}> |
> | GPG: ID 1024/D3498839      Fingerprint 0D99A7FB206605D7 8B35FCDE05B18A5E |
> | http://www.fi.muni.cz/~kas/   Czech Linux Homepage: http://www.linux.cz/ |
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-- ----------------------------------------------------------------------------
Maxwell Spangler                                                
Program Writer                                              
Greenbelt, Maryland, U.S.A.                         
Washington D.C. Metropolitan Area