Re: HPT374 IDE problem with 2.6.21.* kernels

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello, I wrote:

>>>> This looks promising. Using a vanilla 2.6.22-rc3 I was able to 
>>>> reproduce
>>>> the problem within a few seconds. With the above modification the 
>>>> machine
>>>> is running under heavy disk I/O without problems since 30 minutes...

>>> Did it fix the problem for good?

>> It seems so far. There hasn't been any problem since I've applied the 
>> fix.

>>> Sergei, do we need to disallow UDMA6 completely on HPT734 or
>>> is it only an issue with some problematic devices (=> blacklist)?

>    Note that I didn't change what the old code was doing in this regard 
> -- although the HPT374 spec does *not* say that UDMA6 is supported, it 
> had been enabled. What have *really* changed for HPT374 was:

    No, I've lied (my memory haven't served and I've finally forgot to check 
myself).  It was me who enabled it by default (that there should have been no 
option to do this is another question). :-<

> - in 2.6.20-rc1, the driver switched to using the actual 33 MHz timing 
> table
>   instead of the old one, matching 50 MHz (and so, severely underclocked);

> - in 2.6.2-rc1, the driver switched from 33 MHz PCI to 66 MHz DPLL clock.

>    Disallowing UDMA6 would clock the chip with 50 MHz DPLL, howewer, the 
> original report claimed that something has changed to worse between 
> 2.6.21.1 and .3 but nothing changed in drivers/ide/ between those 
> releases...

>>> Either way we need to fix it somehow for 2.6.22.

>> For the record: this HTP374 is running with a quite outdated firmware 
>> (1.22) - maybe newer firmwares work correctly. I'm going to upgrade 
>> the firmware to the latest one (which was released in 2004...), but 
>> unfortunately in the upcoming 2-3 weeks I won't have access to this 
>> machine, so I can't check the case within the release cycle of 2.6.22. 
>> If you were interested I would post the result of the firmware upgrade.

>    I don't think this will matter...

>> Regards,
>>   Sandor

MBR, Sergei