Keyboard is frozen on boot of 2.3.41

[Phillip Ezolt]

FWIW,
	I saw keyboard lockups with 2.2.12 on my old Digital Laptop
when kbd_read_status() was called too quickly, too many times in a row. 

Look at the while loop in "handle_kbd_event(void)". The ps2 status
register can really be hammered. 

By adding an "mdelay(1);" before the second  "status = kbd_read_status();",
everything works fine. 

That may just mask another issue, but it fixed my problem. ;-) 

--Phil

Compaq:  High Performance Server Division/Benchmark Performance Engineering 
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Phillip.Ezolt en compaq.com        |C|O|M|P|A|Q|        ezolt en perf.zko.dec.com
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On Sun, 30 Jan 2000, Linus Torvalds wrote:

> 
> 
> On Sun, 30 Jan 2000, Michael Neuffer wrote:
> > 
> > The only test that so far had any impact was the suggestion to 
> > disable the toshiba workaround. With the workaround enabled I get the
> > "Timeout - AT keyboard not present ?" warning after starting gpm. 
> > If it is disabled, I do not hit this code path.
> 
> [ Tee-dee-tee-dee-tee-dee theme from "The Twilight Zone" ]
> 
> Basically, the mouse open routine does:
> 
>         kbd_write_command_w(KBD_CCMD_MOUSE_ENABLE);     /* Enable the
>                                                            auxiliary port on
>                                                            controller. */
>         aux_write_ack(AUX_ENABLE_DEV); /* Enable aux device */
>         kbd_write_cmd(AUX_INTS_ON); /* Enable controller ints */
> 
>         send_data(KBD_CMD_ENABLE);      /* try to workaround toshiba4030cdt problem */
> 
> and nothing more. The "Timeout" message comes from the final
> "send_data()", which seems to imply nothing more than the fact that the
> keyboard has already locked up by that time.
> 
> Now why any other driver _could_ make a difference here is very very
> unclear. It might be a subtle timing issue, and nothing more. Or it migth
> be something truly subtle indeed.
> 
> The fact that the keyboard does come back when the mouse is closed again
> certainly implies that whatever the interaction is, it's not some other
> driver (ie USB or PCMCIA) just stomping on the keyboard state by mistake.
> It really is internal to the mouse/keyboard driver, and some other driver
> just makes it show up.
> 
> More suggestions, if you have the time and the energy:
> 
>  - try to use the "kbd-reset" kernel command line at bootup, see if that
>    makes any difference (it does a full keyboard init sequence at bootup,
>    and it has been known to matter on some machines).
> 
>  - disable the keyboard before changing the controller mode in open_aux(),
>    and re-order the operations, ie make the init sequence look like this:
> 
> 	kbd_write_command_w(KBD_CCMD_MOUSE_ENABLE);	/* Enable mouse controller */
> 
> 	send_data(KBD_CMD_DISABLE);			/* Disable keyboard during mode set */
> 	kbd_write_cmd(AUX_INTS_ON);			/* Enable controller ints for both keyboard and mouse */
> 	send_data(KBD_CMD_ENABLE);			/* Enable keyboard again */
> 
> 	aux_write_ack(AUX_ENABLE_DEV);			/* Enable the mouse itself */
> 
>    which actually makes a lot more sense than the current one (makes the
>    mouse and keyboard controller and device "enabledness" be more regular:
>    both controllers are enabled during the mode set, but both devices are
>    disabled until after the mode-set is complete.
> 
> The keyboard controller documentation actually seems to imply that the
> keyboard should be disabled during the mode set, so the above change in
> setup may actually fix a real bug. Whether it's the bug that causes
> problems, who knows?
> 
> 			Linus
> 
> 
> -
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