Re: [PATCH] x86: warn on apic error

[Cyrill Gorcunov <gorcunov@gmail.com>]

[Maciej W. Rozycki - Sun, Jul 20, 2008 at 12:08:23AM +0100]
| On Sat, 19 Jul 2008, Cyrill Gorcunov wrote:
| 
| > [Maciej W. Rozycki - Fri, Jul 18, 2008 at 08:09:20PM +0100]
| > | On Fri, 18 Jul 2008, Cyrill Gorcunov wrote:
| > | 
| > | > iirc, they all were there (though some error codes are specific for
| > | > particular processor classes like P4, pentium and other - don't remeber
| > | > you could check intel dev manual for this).
| > | 
| > |  This is an error in some newer Intel documents -- the set of supported
| > | bits is the same for all APICs implementing the ESR register and the error
| > | interrupt (the 82489DX is the one to provide neither).
| > | 
| > |   Maciej
| > |
| > 
| > But Maciej, Intel doesn't claim about absence of bit but
| > rather about their 'reserved' state so checking the reserved
| > bit could be false alarm if it was being set by some reason.
| 
|  As I say -- all later manuals have an error here (not the first and
| presumably not the last one), where they state the invalid register error
| has been only implemented since the P6.  This is not true -- go find the
| Pentium manual or experiment with actual hardware to see otherwise.  No
| new bits have been added since the introduction of the ESR, so there is no
| issue with bits to mask out on older silicon.
| 
|  Obviously the checksum and accept error bits are valid for APICs using
| the dedicated inter-APIC bus only as for the FSB they are irrelevant.  
| They have to be hardwired to zero for backward compatibility though.
| 
|   Maciej
| 

Thanks a lot, Maciej!

		- Cyrill -