Re: [PATCH] pata_it8213: MWDMA0 is unsupported

Sergei Shtylyov
2009-12-03T22:06:52Z

Hello.

Jeff Garzik wrote:

>>>> MWDMA0 timings cannot be met with the PIIX based controller
>>>> programming interface.
>>
>>>> This change should be safe as this is how we have been doing
>>>> things in IDE it8213 host driver for years.
>>
>>>> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
>>>> ---
>>>> Verified with the documentation (similar case as with pata_efar).
>>
>>> Uhhh, no...
>>
>>> Too many damn drivers.
>>
>>> Too much damn duplication.
>>
>>> Too much damn subtle differences here and there.
>>
>>> The hardware is probably fine for MWMDA0 when it comes to
>>> pata_{efar,it8213},
>>> it just not documented properly in the data sheet.
>>
>> How so with pata_efar? The active/recovery bitfields are still 2-bit
>> wide, no?
>
> So.... pata_it8213 is fine for MWDMA0, then?

No, TTBOMK. I just have no datasheet. However, it's programmed
overclocked and even in theory the cycle time cannot exceeed 600 ns vs
480 ns spec'ed.

> Jeff

MBR, Sergei