linux-kernel - Re: [git pull] Input updates for 2.6.33-rc2

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Date:	Thu, 31 Dec 2009 11:50:59 -0800 (PST)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
cc:	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>
Subject: Re: [git pull] Input updates for 2.6.33-rc2

On Wed, 30 Dec 2009, Dmitry Torokhov wrote:
>
> Dmitry Torokhov (7):
>       Input: speed up suspend/shutdown for PS/2 mice and keyboards

Btw, the thing I like best about this commit is how it adds some comments 
on the keyboard commands.

That said, the naming and the comments aren't all that wonderful. I don't 
think you should use the word "RESET" for command f5/f6: the command is 
called "Set Default" (and ".. Disable" for f5), and there is no actual 
reset involved. 

So I suspect the command should be renamed to

	#define ATKBD_CMD_SET_DEFAULTS_AND_DISABLE	0x00f5
	#define ATKBD_CMD_SET_DEFAULTS			0x00f6

and then the comments wouldn't even be needed (and anybody reading the 
code would not have to look them up in the header file).

And then "ATKBD_CMD_RESET_BAT" should probably just be "ATKBD_CMD_RESET" 
(I wonder what the "BAT" part is all about?)

Oh, and command F5h is not always a "set defaults and disable". For some 
(all?) PS/2 mice it seems to be _just_ a "disable", and I'm not at all 
sure you should have used it for the psmouse_cleanup() function. You used 
to do a

	psmouse_reset(psmouse);

which sent a full reset to the mouse (and waits for the two-byte ACK). It 
did _not_ disable the mouse - that happened earlier in 
psmouse_deactivate(), when you sent it the PSMOUSE_CMD_DISABLE command.

You changed that 'psmouse_reset()' to

	/*
	 * Reset the mouse to defaults (bare PS/2 protocol).
	 */
	        ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);

which now disables it again, only to then later do

	/*      
	 * Some boxes, such as HP nx7400, get terribly confused if mouse
	 * is not fully enabled before suspending/shutting down.
	 */     
	        ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);

which seems odd. IOW, Why do you do a "set defaults and disable" followed 
by a "enable", when you already had it disabled?

I think the PSMOUSE_CMD_RESET that _used_ to be there would re-enable most 
mice, but now that you don't even do that any more, I get the feeling that 
the "set defaults and disable" should be just a "set defaults".

(You may have good reasons for having picked the "and disable" command. I 
just wonder what they are)

		Linus
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