Re: SiS APIC, hacker looking for docs/help, was : Re: 2.6.4 underheavy ioload disables sis5513 DMA

From: Lionel Bouton
Date: Thu Mar 18 2004 - 07:28:53 EST


Michael Frank wrote the following on 03/18/2004 12:52 PM :



Is reading the arch/i386/kernel/*pic* files (and probably others) enough
to start or is there somewhere else to look for information ?


Dunno how DMA timeout is related to interrupts or are you suggesting it
is loosing dma-complete interrupts?


I don't know the details (yet I hope), but I'm quite sure that interrupt handling in XT-PIC mode leads to problems on several SiS configurations (when you reorganize PCI cards in a system and the behaviour changes or when you disable the VGA IRQ and some things start to work, the suspect becomes obvious). One user reported that putting 2 disks on one channel instead of one on each (so 1 IRQ used instead of 2) solve instability issues too... I ruled out IDE driver problems several times by repeatedly checking the code and the run-time register values against known-good values. My lack of knowledge on the interrupt handling details is what prevents me from being 100% sure that the problem lies here. This is why I'm willing to work on this subject.

Same board runs same and higher loads with 2.4.2[345] flawlessly. Also
8 hours OK with 2.4.26-pre4 last night + 430 cycles of swsusp2.


Now I remember why your name ringed a bell ! Thanks for your testing work on swsusp, my amount of free time went up thanks to 2.4's swsusp.

Regards,

--
Lionel Bouton - inet6
---------------------------------------------------------------------
o Siege social: 51, rue de Verdun - 92158 Suresnes
/ _ __ _ Acces Bureaux: 33 rue Benoit Malon - 92150 Suresnes
/ /\ /_ / /_ France
\/ \/_ / /_/ Tel. +33 (0) 1 41 44 85 36
Inetsys S.A. Fax +33 (0) 1 46 97 20 10


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/