Messages in this thread |  | | Date | Thu, 26 Nov 2009 21:12:59 +0300 | | From | Sergei Shtylyov <> | | Subject | Re: [PATCH] pata_it8213: MWDMA0 is unsupported |
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Bartlomiej Zolnierkiewicz 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?
>>Yes but when TIMEx bit is disabled we are using XFER_PIO_SLOW timings.
600 ns cycle vs spec'ed 480 ns? Is it really worth it?
>>All data sheets including original Intel ones are a complete crap when it >>comes to explicitly documenting this behavior.
> OTOH all drivers set TIMEx for MWDMA0 currently.. ?
... which would give a grossly overclocked timing.
> -- > Bartlomiej Zolnierkiewicz
MBR, Sergei
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