2001-02-09 16:33:10

by Petr Vandrovec

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

On 9 Feb 01 at 16:58, Vojtech Pavlik wrote:

> Unfortunately the PCI speed measuring code needs help from the chipset
> itself, so it isn't possible to implement in generic code. Maybe a
> callback could be added to the chipset-specific drivers, though ...
>
> I do have some plans with ide-pci.c, so ...

Is not PCI speed determined by host-bridge setting (and not by IDE
interface)? In that case we should determine bus speed on PCI bus scan
using chipset specific drivers. Other non IDE devices, such as matroxfb,
may be interested in PCI speed too.
Best regards,
Petr Vandrovec
[email protected]


2001-02-09 16:36:50

by Vojtech Pavlik

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

On Fri, Feb 09, 2001 at 05:29:52PM +0000, Petr Vandrovec wrote:

> > Unfortunately the PCI speed measuring code needs help from the chipset
> > itself, so it isn't possible to implement in generic code. Maybe a
> > callback could be added to the chipset-specific drivers, though ...
> >
> > I do have some plans with ide-pci.c, so ...
>
> Is not PCI speed determined by host-bridge setting (and not by IDE
> interface)?

I found no way of measuring the PCI speed than by doing an IDE PIO
transfer unfortunately. Measuring all other PCI transactions gives bad
results, because it is dependent on waitstates and other variables.

> In that case we should determine bus speed on PCI bus scan
> using chipset specific drivers. Other non IDE devices, such as matroxfb,
> may be interested in PCI speed too.

Not the case, sorry. An IDE drive is needed. However, it still might be
worth to pass the PCI speed to other drivers ...

--
Vojtech Pavlik
SuSE Labs

2001-02-10 06:08:16

by Andre Hedrick

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

On Fri, 9 Feb 2001, Petr Vandrovec wrote:

> On 9 Feb 01 at 16:58, Vojtech Pavlik wrote:
>
> > Unfortunately the PCI speed measuring code needs help from the chipset
> > itself, so it isn't possible to implement in generic code. Maybe a
> > callback could be added to the chipset-specific drivers, though ...
> >
> > I do have some plans with ide-pci.c, so ...
>
> Is not PCI speed determined by host-bridge setting (and not by IDE
> interface)? In that case we should determine bus speed on PCI bus scan
> using chipset specific drivers. Other non IDE devices, such as matroxfb,
> may be interested in PCI speed too.

that file will most likely go away in 2.5


Andre Hedrick
Linux ATA Development
ASL Kernel Development
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2001-02-10 09:05:16

by Vojtech Pavlik

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

On Fri, Feb 09, 2001 at 10:06:39PM -0800, Andre Hedrick wrote:

> > > Unfortunately the PCI speed measuring code needs help from the chipset
> > > itself, so it isn't possible to implement in generic code. Maybe a
> > > callback could be added to the chipset-specific drivers, though ...
> > >
> > > I do have some plans with ide-pci.c, so ...
> >
> > Is not PCI speed determined by host-bridge setting (and not by IDE
> > interface)? In that case we should determine bus speed on PCI bus scan
> > using chipset specific drivers. Other non IDE devices, such as matroxfb,
> > may be interested in PCI speed too.
>
> that file will most likely go away in 2.5

Good, it should.

--
Vojtech Pavlik
SuSE Labs

2001-02-10 13:31:26

by Martin Mares

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

Hello!

> Not the case, sorry. An IDE drive is needed. However, it still might be
> worth to pass the PCI speed to other drivers ...

But beware, the timing should be a per-bus value.

Have a nice fortnight
--
Martin `MJ' Mares <[email protected]> <[email protected]> http://atrey.karlin.mff.cuni.cz/~mj/
The first myth of management is that it exists.

2001-02-10 14:39:32

by Jonathan Morton

[permalink] [raw]
Subject: Re: [preview] VIA IDE 4.0 and AMD IDE 2.0 with automatic PC

>> Not the case, sorry. An IDE drive is needed. However, it still might be
>> worth to pass the PCI speed to other drivers ...
>
>But beware, the timing should be a per-bus value.

Indeed - remember the PowerMac G3 (blue & white) and the "Yikes" G4 have a
66MHz PCI slot in place of the AGP slot used in later G4s, with the
remaining 3 PCI slots being 33MHz 64-bit.

--------------------------------------------------------------
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mail: [email protected] (not for attachments)
big-mail: [email protected]
uni-mail: [email protected]

The key to knowledge is not to rely on people to teach you it.

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