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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH] powerpc: Pegasos keyboard detection
Date: Tue, 31 Jul 2007 23:26:35 +0200
To: Alan Curry <pacman@theworld.com>
Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org
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> As of 2.6.22 the kernel doesn't recognize the i8042 keyboard/mouse 
> controller
> on the PegasosPPC. This is because of a feature/bug in the OF device 
> tree:
> the "device_type" attribute is an empty string instead of "8042" as the
> kernel expects. This patch (against 2.6.22.1) adds a secondary 
> detection
> which looks for a device whose *name* is "8042" if there is no device 
> whose
> *type* is "8042".
>
> Signed-off-by: Alan Curry <pacman@world.std.com>
>
> --- arch/powerpc/kernel/setup-common.c.orig	2007-07-24 
> 19:04:17.000000000 -0500
> +++ arch/powerpc/kernel/setup-common.c	2007-07-24 19:06:36.000000000 
> -0500
> @@ -487,6 +487,10 @@ int check_legacy_ioport(unsigned long ba
>  	switch(base_port) {
>  	case I8042_DATA_REG:
>  		np = of_find_node_by_type(NULL, "8042");
> +		/* Pegasos has no device_type on its 8042 node, look for the
> +		 * name instead */
> +		if (!np)
> +			np = of_find_node_by_name(NULL, "8042");

[I know it already got merged, I'm behind on mail, but anyway...]

Could board-specific quirks like this please always include a
check for that board?  Or, even better, do a fixup in the
bootwrapper.

In this case the workaround won't likely trigger on the wrong
boards, but "just a little bit" more dangerous workarounds
_will_, and the law of big numbers works against us...


Segher