Re: Nvidia cable detection problems (was [PATCH] amd74xx: don't configureudma mode higher than BIOS did)

From: Tejun Heo
Date: Mon Feb 05 2007 - 14:16:28 EST


Bartlomiej Zolnierkiewicz wrote:
> Hi,
>
> On 2/5/07, Tejun Heo <htejun@xxxxxxxxx> wrote:
>> Alan wrote:
>> >> The *real* solution is to use the BIOS ACPI _GTM _STM methods for
>> this.
>> >> Then you can remove all chipset specific knowledge from the IDE
>> driver.
>> >> This is what the MS driver does on Windows, so you know it's
>> received a
>> >> lot of testing from NVIDIA and board vendors.
>
> Allen, thanks for quick reply.
>
> Your mail explained the issue pretty well and saved us a lot of time.

My thanks too.

>> > Well we can certainly do some of that if ACPI is present and active. In
>> > particular since _GTM will give us current modes allowing for
>> hotplug and
>> > post BIOS boot kexec etc it ought to be safe to do Tejun's hack that
>> way.
>> > We could even probe UDMA3+ capable devices by doing _STM to a high mode
>> > and _GTM to determine the cable type 8)
>
> agreed
>
>> Glad to see the problem getting solved. Now that we know the solution,
>> any volunteers? :-)
>
> Well, since you posted the initial patches and have the affected
> hardware... 8)

I'll be on the road for the next two weeks and Alan seems to have taken
it already. :-)

--
tejun
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