Re: [RFC] IDE 80-core cable detect - chipset-specific code to over-ride eighty_ninty_three()

[Willy Tarreau]

On Sun, Feb 08, 2004 at 11:45:18AM +1100, Athol Mullen wrote:
> Before I modified eighty_ninty_three(), it returning 0 caused the _indicated_ 
> mode to drop to UDMA33.  Check in /proc/ide/piix to see what mode the driver 
> tells you.  IIRC (could be wrong), dmesg and hdparm both believe it to be in 
> UDMA33 while the init code and /proc/ide/piix both showed it as UDMA5.

I captured dmesg and /proc/ide/piix, but forgot to post them. They're at work
now. But I did the change, by commenting out the call to eighty_ninety_three()
in piix.c, and my disks came back to 54 MB/s each, and 64 MB/s cumulated.
dmesg showed UDMA33 before and now displays UDMA100 again. But I obviously
cannot let it like that because if I install this kernel in a 40-pin machine,
I will get some surprizes !

> I'm starting to wonder if my ICH5 _is_ actually running UDMA5...  It's doing 
> 21MB/s, which I've been blaming on the old 30G Quantum, whereas the ICH4 with 
> a 120G drive is doing 56MB/s...  I think I checked the bit flags in 
> /proc/ide/ide0/config and it showed up as UDMA5.

I'm certain that this one changed before and after the patch, but I cannot
tell you what the differences were.

> >> I'm not certain exactly how this would be implemented, but I'd like to see 
> >> eighty_ninty_three() check for chipset-specific detection code, and use the 
> > well, why not in piix:piix_ratemask() around line 315 ?
> 
> I could put it there, but I was actually intending to use it to also return a 
> value properly for eighty_ninty_three(), and figured that it would need to be 
> a separate routine - I expect that the module structure needs to change, and 
> that's where I'm not sure - it could affect _all_ ide drivers.  There might 
> be others that have their own specific detection code, and what I'm looking 
> to do is establish the framework for that.
 
I understand. But could you please post your ICH5 detection code so that I
can try it on this machine. I still can play with it for a few days before
it gets racked. And I can try with both 40 and 80-pin cables.

> business .sig wasn't supposed to get tacked on after my usenet .sig...  It 
> _was_ a spam-free email address.  :-(

Now the only thing you can do is to count how many days elapse before you
get your first spam...

Regards,
Willy

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