Re: PNX8550 Broken on Linux 2.6.24 - Interrupt issues?

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

Hello.

Ralf Baechle wrote:

>>I have been happily using Linux 2.6.22.1 for ages on PNX8550 (STB810).
>> I have recently decided to step up and move onto Linux 2.6.24 series.
>>However I am not getting very far. :-(

    Heh, Daniel, you're not alone -- the Alchemy code got much more breakage 
before 2.6.24... :-)

>>The board crashes as soon as local_irq_enable is called in main.c

>>I was wondering if anyone out there might also be running on an
>>STB810/JBS PNX8550 based system and have any ideas as to why I am
>>crashing.
>>I know that PNX8550 does not enable the R4K Clock source stuff as the
>>chip is a bit 'special' and requires the two timers to be used instead
>>of one.

> csrc-r4k.c and cevt-r4k.c assume a standard compliant R4000-style
> c0_count and c0_compare register.  The PNX chips violate the expected
> behaviour badly so can't use these functions.

> But that's not very much of a problem.  The timer code is module and
> it is easy to write something like csrc-pnx.c and cevt-pnx.c to drive
> a PNX style count/compare timer.

    The PNX counter 0 can still be used as the standards clocksource with some 
ad-hockery (setting comparator to all ones and hooking the interrupt to clear 
it) but Vitaly went another way using counter 1 for clocksource, and counter 0 
as clockevent...

> Will look over the code to see if I can spot what crashes the PNXes.

>   Ralf

WBR, Sergei