Messages in this thread | | | Date | Mon, 9 Jan 2006 12:54:52 -0500 | From | Dmitry Torokhov <> | Subject | Re: PROBLEM: PS/2 keyboard does not work with 2.6.15 |
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On 1/9/06, Alan Stern <stern@rowland.harvard.edu> wrote: > On Mon, 9 Jan 2006, Dmitry Torokhov wrote: > > > > It would be nice to know which part of the usb-handoff code causes the > > > problem. > > > > Well, it's not handoff code causing problems per se, it's just that it > > does not look like it performs handoff. If it did then disabling USB > > legacy emulation in BIOS would have no effect, right? > > On the other hand, if the BIOS worked correctly then the ps/2 port would > have no problems regardless of whether USB legacy emulation was on or off. > Given that the keyboard works during bootup, I see only two possibilities: > > The USB handoff code somehow causes the BIOS to mess up the > state of the 8042; > > The 8042 driver interacts badly with the firmware when USB > legacy emulation is on, and the USB handoff code doesn't > successfully turn off legacy emulation. > > My earlier suggestion was an attempt to test the first possibility. The > second is harder to test because it implies problems in both the 8042 > driver and the USB handoff code. >
My experience is that USB legacy emulation in BIOS + ACPI works as long as you do not touch it and gets terribly confused if someone tries to actually use i8042 (like enable active multiplexing mode with 4 AUX ports). As soon as BIOS takes its dirty hands off i8042 everything works fine.
The problem it seems that when usb-handoff code was moved from pci quirks and enabled inconditionally something happened so it stopped doing handoff.
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