Re: [BUG 2.6.20-rc2] atkbd.c: Spurious ACK

[Dmitry Torokhov <dtor@insightbb.com>]

On Friday 29 December 2006 00:17, Rene Herman wrote:
> Dmitry Torokhov wrote:
> 
> >>> The change to suppress ACKs from paic blinking is already in Linus's
> >>> tree. I just tried booting with root=/dev/sdg and I had leds blinking
> >>> but no messages from atkbd were seen.
> >>>
> >>> Could it be that you loaded older kernel by accident? Does anybody
> >>> else still seeing "Spurios ACK" messages during kernel panic?
> >> Well, no, I'm really on 2.6.20-rc2, from a freshly cloned tree. And I do 
> >> get atkbd.c complaining at me when I boot with root=/dev/wrong-device.
> >>
> >> Could you point me to the changeset in question? I couldn't find it 
> >> searching for "leds" in the log.
> >>
> > 
> > http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=817e6ba3623de9cdc66c6aba90eae30b5588ff11
> 
> Yes, I do have that in my tree. From the looks of it it's probably not 
> surprising, but the following gets me blinking leds without the spurious 
> ACK messages. Maybe still useful to know?
> 
> diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
> index debe944..9c70d34 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -371,7 +371,7 @@ static irqreturn_t i8042_interrupt(int i
>   	if (unlikely(i8042_suppress_kbd_ack))
>   		if (port_no == I8042_KBD_PORT_NO &&
>   		    (data == 0xfa || data == 0xfe)) {
> -			i8042_suppress_kbd_ack = 0;
> +			/* i8042_suppress_kbd_ack = 0; */
>   			goto out;

That would indicate that your keyboard generates multiple acks... I wonder
if you could boot with i8042.debug=1 and somehow capture the data flow
during panic (do you have a digital camera?).

-- 
Dmitry