Re: sata_promise / libata defaulting to UDMA/33

From: Alan Cox
Date: Thu Aug 03 2006 - 12:53:10 EST

Ar Gwe, 2006-08-04 am 00:31 +0800, ysgrifennodd Marc:
> Hi.
> I'm having great difficulty solving a problem I've encountered. I have a
> Promise Fastrak TX4000 card:

We knock things down to UDMA33 if they are on an unsuitable cable. The
rest of the displayed data looks correct.

> ata2: PATA max UDMA/133 cmd 0xF8ABC280 ctl 0xF8ABC2B8 bmdma 0x0 irq 137

Controller does 133

> ata2: dev 0 cfg 49:2f00 82:346b 83:7f01 84:4003 85:3469 86:3c01 87:4003 88:203f
> ata2: dev 0 ATA-6, max UDMA/100, 312581808 sectors: LBA48

Devices does UDMA 100
> <b>ata2: dev 0 configured for UDMA/33</b>

So this appears to be a cable confusion. One thing that was fixed in
recent patches was a bug where if the core code decided something was
PATA but the drive setup was in fact SATA it incorrectly clipped to

> I'm currently running kernel In the controller's BIOS I've created 3
> 'stripe' arrays with 1 disk per array, the BIOS shows the 3 drives as U5 (UDMA
> mode 5 - which is UDMA/100 right?).


> I've searched high and low but haven't found an answer to this problem. Help
> appreciated. Please - I'm getting dismal performance.

I think the needed patch is in 2.6.18-mm, not sure about 2.6.18-rc base.
Jeff Garzik would be able to verify what has it merged.

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