Re: Sym53c8xx tape corruption squashed! (was: Re: SCSI Tape corruption
Geert Uytterhoeven (firstname.lastname@example.org)
Sat, 29 Dec 2001 14:23:14 +0100 (MET)
On Sat, 29 Dec 2001, [ISO-8859-1] Gérard Roudier wrote:
> On Fri, 28 Dec 2001, Geert Uytterhoeven wrote:
> > The sym-2 driver has a define for modifying the PCI latency timer
> > (SYM_SETUP_PCI_FIX_UP), but it is never used, so I see no corruption.
> By default sym-2 use value 3 for the pci_fix_up (cache line size + memory
> write and invalidate). The latency timer fix-up has been removed, since it
> is rather up to the generic PCI driver to tune latency timers.
> > Is this a hardware bug in my SCSI host adapter (53c875 rev 04) or my host
> > bridge (VLSI VAS96011/12 Golden Gate II for PPC), or a software bug in the
> > driver (wrong burst_max)?
> Great bug hunting!
> It is about certainly not a software bug in the driver. Any latency timer
> value should not give any trouble if hardware was flawless. Just the PCI
> performances could be affected.
I played a bit with sym-2 and setpci. Everything goes fine as long as the PCI
latency timer value is smaller than 0x16 (yes, at first I thought it was
decimal, but setpci parameters are in hex).
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- email@example.com
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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