Re: [RESOLVED]: kernel hangs on CD-R HP8100i if compiled w/ VIA IDE

Vojtech Pavlik (vojtech@suse.cz)
Fri, 9 Feb 2001 22:44:00 +0100


On Fri, Feb 09, 2001 at 10:18:05PM +0100, Henryk Paluch wrote:

> Shortly: kernel (2.2.x, 2.4.x) hangs on CD-R HP8100i, VIA KT133 chipset
> (w/ ATA100 support) if kernel is compiled with VIA IDE chipset support.
> Please, see my previous post from 21 Jan 2001 for full description.
>
> After little tweaking via82cxxx.c driver I found, that the cause is
> 'Prefetch Buffer: ' (/proc/ide/via) - if disabled for appropriate IDE
> channel, everything works well. It also explains, why the kernel works
> properly if VIA IDE support is not compiled in - BIOS leaves Prefetch
> disabled (I hacked that driver a bit more to show chipset configuration
> either before and after modification).
>
> So I have a little question: What could be a clean way, to make a kernel
> option to disable prefetch for VIA (use something like 'ide1=noprefetch'?)
> Any idea?

Since version 2.30 of the VIA driver (2.4.2-pre2), the driver leaves
prefetch as is set by BIOS. It seems that ATAPI devices need this set to
off at least on some of the VIA chips.

-- 
Vojtech Pavlik
SuSE Labs
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