Re: [2.6.22.2 review 06/84] Add a PCI ID for santa rosas PATAcontroller.

From: Andrew Morton
Date: Thu Aug 09 2007 - 15:41:40 EST


On Wed, 8 Aug 2007 01:39:12 +0200
Chr <chunkeey@xxxxxx> wrote:

> On Tuesday, 7. August 2007, Greg KH wrote:
> >
> > From: Christian Lamparter <chunkeey@xxxxxx>
> >
> > This is commit c1e6f28cc5de37dcd113b9668a185c0b9334ba8a which is
> > merged during 23-rc1 window. Considering the popularity of these
> > chips, I think including it in -stable release would be good idea.
> >
> > Signed-off-by: Christian Lamparter <chunkeey@xxxxxx>
> > Signed-off-by: Jeff Garzik <jeff@xxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
> >
>
> I did not receive any complains. I guess it's stable enough for -stable ;-) ...
>
> ---
>
> Not OT:
>
> There is another outstanding issue with ata_piix.c.
> Intel has never officially supported anything faster than PATA 100MB/s.
>
> But, the ata_piix.c driver "define" the ICH5 & ICH7 as UDMA6 (aka 133MB/s) capable.
> [ Well, no one has probably noticed it before, because there is bug in do_pata_set_dmamode...
> Just look at libata_atapiix_enable_real_udma133.patch and you'll see what wrong with it. ]
>
> Here are Intel's datasheets for the affected chipsets:
> ICH5 Datasheet: http://www.intel.com/design/chipsets/datashts/252516.htm
> (See note on page 183: "... the ICH5 supports reads at the maximum rate of 100MB/s.")
>
> ICH7 Datasheet: http://www.intel.com/design/chipsets/datashts/307013.htm
> (See first note on page 190: "... the ICH7 supports reads at the maximum rate of 100MB/s.")
>
> -
>
> They are two different ways to deal with it:
>
> - Either -
>
> 1. replace all ich_pata_133 with ich_pata_100.
> (libata_atapiix_disable_udma6.diff - diff from 2.6.22 )
>
> - Or -
>
> 2. keep all ich_pata_133 and fix the bug in "do_pata_set_dmamode".
> (libata_atapiix_enable_real_udma133.patch - diff from 2.6.22)
> If there are any concerns about the safety of the patch patch:
> http://lkml.org/lkml/2007/7/6/292 (It was already tested by an Intel employee,
> but I guess a bit more user input is necessary here... )
>
> Both ways have their pros and cons. Unfortunately, I don't have the time to follow this
> discussion right now, so here's a:
>
> Signed-off-by: Christian Lamparter <chunkeey@xxxxxx>
> (Just in case, if one of the patches really gets merged!)
>

You kinda hid these patches rather well.

I chose option 1.



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