Re: [linux-usb-devel] RE: [PATCH] Early USB handoff

[David Brownell]

On Thursday 02 September 2004 1:26 pm, Aleksey Gorelov wrote:

>   While still in real mode, BIOS takes care of interrupts from 
> devices. But once OS takes control over and goes to protected 
> mode, there is no easy way for BIOS to detect that and disable HC.

I find myself a bit unsettled at the notion of not really being
able to blame this behavior on BIOS bugs.  What's the world
coming to any more?!


> So, one should either avoid 'sharing' it with other devices (at
> IRQ routing stage), or reprogram HC in native OS mode first (at 
> least disable interrupts).

That sounds like it could explain lots of the init/irq problems we've
had on various systems.  Makes me a lot more interested in seeing
this fix go in ... :)

For backwards compatibility, the early reset should not be the
default.  There aren't many systems where it's a problem.

- Dave
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