Re: IDE: 2.2.19+IDE patches works fine; 2.4.x fails miserably; please

Jonathan Kamens (jik@kamens.brookline.ma.us)
Sun, 25 Nov 2001 16:32:09 -0500


(Responding to E-mail sent to me privately by Mark Hahn....)

> > This clearly isn't a problem with my cables (and I've just wasted over
> > $40 to prove it, unless I can convince Staples to take back the opened
> > cables).
>
> are the cables 18"? lots of places sell 24" cables, which have never
> been valid...

No, both the new cables I put in and my old ones were 18" cables.

> > If it's a problem with my drives, then how is it that I don't have any
> > problems at all when I run 2.2.19+IDE on exactly the same hardware?
>
> 2.2 doesn't contain chipset-specific mode tuning code, afaik.
> in general, it just uses the mode as programmed by the bios.

Perhaps I have not explained myself clearly enough, or perhaps my
understanding of what Andre's 2.2.x IDE patch is, is incorrect.

I am not using stock 2.2. I am using 2.2 plus Andre Hedrick's IDE
backport patch. I thought that the whole point of this patch was to
backport the enhanced IDE functionality from 2.4 back to 2.2.

Without Andre's patch, I wouldn't be able to send you the output of
/proc/ide/pdc202xx, because it wouldn't exist, because (as you point
out) there would be no code in the kernel specific to that chipset.
With the patch, there *is* code in the kernel specific to that
chipset.

> > Bus Clocking : 33 PCI Internal
>
> my best theory is that this is wrong. I assume you're not overclocking,
> but have you scrutinized your bios settings? the ide clock is usually
> hung off the PCI clock, divided down from AGP, divided down from FSB.

This is all Greek to me. Could you translate a bit for the
kernel-internals-impaired? What should I be looking at/for, exactly?

> wrong clocking (or the driver somehow using the wrong timing)
> would explain both the messages you're seeing.

But the settings are the same as those used by 2.2.19+IDE, with which
I'm not having any problems. Here's /proc/ide/pdc202xx when I'm
running 2.2.19+IDE:

PDC20262 Chipset.
------------------------------- General Status ---------------------------------
Burst Mode : enabled
Host Mode : Normal
Bus Clocking : 33 PCI Internal
IO pad select : 10 mA
Status Polling Period : 15
Interrupt Check Status Polling Delay : 13
--------------- Primary Channel ---------------- Secondary Channel -------------
enabled enabled
66 Clocking enabled enabled
Mode PCI Mode PCI
FIFO Empty FIFO Empty
--------------- drive0 --------- drive1 -------- drive0 ---------- drive1 ------
DMA enabled: yes yes yes yes
DMA Mode: UDMA 4 NOTSET UDMA 4 NOTSET
PIO Mode: PIO 4 NOTSET PIO 4 NOTSET

Thanks,

Jonathan Kamens
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