Re: [linux-usb-devel] [PATCH] USB BIOS early handoff only when thewe the driver is configured

From: David Engraf
Date: Thu Aug 02 2007 - 03:08:47 EST




Greg KH schrieb:
> On Wed, Aug 01, 2007 at 09:21:12AM +0200, David Engraf wrote:
>
>> At the moment I have a Jetway/VIA Mainboard which seems to have a
>> problem with the handoff.
>> Evenwhen I wait about 20 seconds the EHCI_USBLEGSUP_BIOS flag is not
>> cleared. I think this is a BIOS
>> bug and I will have to talk to Jetway/VIA.
>>
>
> This sounds like a BIOS bug.
>
I think so too and I have to talk to Jetway/VIA what there is going wrong.
>
>> On the other hand, I don't need the EHCI controller in my kernel, so I
>> think the kernel shouldn't take the
>> handover for the EHCI controller like other OS which do not have an usb
>> driver and so don't know that
>> there is a EHCI_USBLEGSUP_BIOS flag which should be cleared.
>>
>
> We need to do this early to handle a wide range of machines that do very
> nasty things if we do not grab the device as early as possible. Even if
> we do not ever get around to loading that usb driver.
>
> Yeah, hardware sucks at times :(
>
>
Ok, but when we don't habe the driver for the usb controller, I think
the BIOS should control it because
maybe the BIOS found for example a keyboard or mouse and emulates it as
an PS2 keayboard/mouse,
so we could use it without the usb driver. I think that's why they
developed the handoff feature.
Are there any known hardware which has problems when we disable the handoff?

> thanks,
>
> greg k-h
>

Thanks


David Engraf




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