Nvidia cable detection problems & ACPI (beware, slight off-top)

[Oleg Verych <olecom@flower.upol.cz>]

> Unfortunately there's no standard way to do host side cable detect on
> nForce systems without going through ACPI.  It's done through a GPIO
> pin.  Board vendors are free to reallocate which GPIO pin is used for
> this feature.  

Want to know how to make incompatibility? "Ask me How!(tm)".

Regarding ACPI, please see Linus at first,
<http://permalink.gmane.org/gmane.linux.kernel/487507>

And then, are you sure MSACPI will be compatible with any competitor
in near future?

[]
> 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.

Do you mean: with all possible crutches?

I'm very upset, that hardware nvidia-lego forces system software (and
programmers) to know "unfortunately no standard" ways of desinging
things... One read-only-for-os, hardware set bit in kind of control
register isn't possible at all, tphu. BDU market (BDU=brain dead user),
which Microsoft dominates, makes BDD (... designers ;)

> -Allen

No, you don't.

Do you know, why top posting is bad?

Hi.

> From: "Allen Martin"
> Newsgroups: gmane.linux.kernel,gmane.linux.ide
> Subject: RE: Nvidia cable detection problems (was [PATCH] amd74xx: don't configure udma mode higher than BIOS did)
> Archived-At: <http://permalink.gmane.org/gmane.linux.kernel/489859>
> Date: Mon, 5 Feb 2007 09:08:03 -0800


>> -----Original Message-----
>> From: Bartlomiej Zolnierkiewicz [mailto:bzolnier@gmail.com] 
>> Sent: Monday, February 05, 2007 7:09 AM
>> To: Allen Martin
>> Subject: Fwd: Nvidia cable detection problems (was [PATCH] 
>> amd74xx: don't configure udma mode higher than BIOS did)
>> 
>> Hi Allen,
>> 
>> Would it be possible to get some help on this issue?
>> 
>> Thanks,
>> Bart
>> 
>> ---------- Forwarded message ----------
>> From: Tejun Heo <htejun@gmail.com>
>> Date: Feb 5, 2007 3:50 PM
>> Subject: Re: Nvidia cable detection problems (was [PATCH] amd74xx:
>> don't configure udma mode higher than BIOS did)
>> To: Alan <alan@lxorguk.ukuu.org.uk>
>> Cc: bzolnier@gmail.com, linux-ide@vger.kernel.org, 
>> linux-kernel@vger.kernel.org
>> 
>> 
>> Alan wrote:
>> [--snip--]
>> >> CK804 IDE, at least mine, reports 80c in a lot of cases where it 
>> >> shouldn't.  I dunno the reason but it also makes drives confused 
>> >> about cable type.  Maybe it has the wrong capacitor 
>> attached or something.
>> >> This is A8N-E from ASUS, probably one of the popular ones 
>> using nf4.
>> >
>> > I take it this was how you came to find every cable related 
>> bug while 
>> > trying to work out what was going on ?
>> 
>> Yeap, pretty much.  I thought fixing drive side cable 
>> detection would fix it, but hell no.
>> 
>> >> When that happens, libata EH does its job and slows the 
>> interface to
>> >> udma33 after quite a few error messages.  On IDE, if this happens, 
>> >> the drive is put into PIO mode making the machine painful to use.
>> >
>> > No the IDE layer does DMA changedown fine, well apart from all the 
>> > error/timer races in the old IDE code.
>> 
>> I dunno.  It always ended up in PIO mode in my case.  I can 
>> post the log if necessary.
>> 
>> [--snip--]
>> >> I agree with you that this is a hack and ugly as hell.  I 
>> don't like 
>> >> it either, but it solves an existing problem which could have and 
>> >> possibly will hit many users.  So, I think this problem should at 
>> >> least be verified.  If it's just my BIOS/motherboard 
>> that's crazy, I 
>> >> have no problem forgetting about this.
>> >
>> > It certainly seems to be Nvidia specific, so perhaps Nvidia can 
>> > provide more details on the Nforce4 cable detection ? As 
>> with a lot of 
>> > Nvidia stuff there was much reverse engineering involved in the 
>> > original code base.
>> 
>> Hmmm... Anyone happen to have working nvidia contact?
>> 
>> > And if its a specific board or couple of boards then we 
>> should perhaps 
>> > use DMI to match them specifically.
>> >
>> >> So, anyone with CK804 (a.k.a NF4) up for some testing?
>> >
>> > If it still goes I've got a rather iffy NF3 but not an NF4 handy.
>> 
>> Yeah, please.  If I connect a hdd at the end of 40c cable and 
>> leaving the middle connector empty, the 80c bit is always one 
>> and the drive says it's 80c cable while the BIOS configured 
>> mode is correctly udma33.  This is the same for SAMSUNG 
>> SP0802N, Maxtor 91301U3 and HITACHI_DK23BA-20.
>> 
>> --
>> tejun
>> 

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Wha? Cool!

____