Re: [Qemu-devel] "i8042.c: No controller found" -> OS sees no keyboard if I type "in BIOS"

[Tomasz Chmielewski]

Tomasz Chmielewski schrieb:
> When I boot the guest and type (just hit any keys) in the VNC window 
> before the operating system boots, sometimes, the system loads with no 
> keyboard present - as signified in dmesg on guest:
>
> i8042.c: No controller found
>
> As a result, I can't use the keyboard in the VNC window.
>
> If I start qemu process and I don't press any key, I can use the 
> keyboard once the operating system boots.
>
> Rebooting the guest doesn't fix the problem, even if I don't touch the 
> keyboard before the OS boots any more.
> Only stopping the guest and starting a new qemu process fixes the problem.
>
> Anyone else saw it as well? If not, try something like that on your guests:
>
> grep i8042 /var/log/kern*
>
> (or grep "i8042.c: No controller found" /var/log/kern*)
>
> Some more confirmations of this problem in the internet:
>
> http://qemu-forum.ipi.fi/viewtopic.php?f=5&t=4461
> http://osdir.com/ml/fedora-virt/2009-04/msg00066.html
> http://www.proxmox.com/forum/showthread.php?t=1163

drivers/input/serio/i8042.c in the Linux kerne has this:

static int i8042_controller_check(void)
{
        if (i8042_flush() == I8042_BUFFER_SIZE) {
                printk(KERN_ERR "i8042.c: No controller found.\n");
                return -ENODEV;
        }

        return 0;
}


So, can it be that if we type anything on keyboard (or move mouse) while 
Qemu's BIOS is still booting or later in the bootloader (GRUB, lilo), 
some buffer is not flushed and Linux gets confused? And as a result, 
decides there is no keyboard?


--
Tomasz Chmielewski
http://wpkg.org