The keyboard is left powered up during suspend: we shouldn't need to
reset it at all (except on power up). This is so you can touch a key or
the keypad and get the CPU back instanty.
- Jim
On Sun, 2007-04-01 at 21:09 +0200, Jens Axboe wrote:
> Hi,
>
> I took a look at the time spent doing a suspend and resume cycle. In
> general things go pretty fast, most devices handle it really quickly.
> USB is a bit slow (~100 msec), but I ignored that since apparently there
> are already people working on fixing USB suspend (functionality, speed
> of course comes second).
>
> The slowest parts are the keyboard and mouse. psmouse takes ~570 msec to
> resume alone, and the keyboard is no speed daemon at ~269 msecs. Looking
> at the psmouse first, by far the majority of the time is spend resetting
> the device (drivers/input/mouse/olpc.c:olpc_reconnect() ->
> psmouse_reset()). A quick test works fine for me without the reset, but
> that may not be a sound approach. Perhaps deferring a reset to IFF
> olpc_get_model() fails would be more safe?
>
> I'll be playing some more with the timings and testing over the next
> week, do let me know if there's something more urgent in suspend/resume
> area that needs attention.
>
> The kernel used was current olpc-2.6.
>
> diff --git a/drivers/input/mouse/olpc.c b/drivers/input/mouse/olpc.c
> index 5f813f5..d2df132 100644
> --- a/drivers/input/mouse/olpc.c
> +++ b/drivers/input/mouse/olpc.c
> @@ -351,12 +351,19 @@ static int olpc_poll(struct psmouse *psmouse)
> static int olpc_reconnect(struct psmouse *psmouse)
> {
> struct olpc_data *priv = psmouse->private;
> + struct olpc_model_info *info;
> int mode;
>
> - psmouse_reset(psmouse);
> -
> - if (!(priv->i = olpc_get_model(psmouse)))
> - return -1;
> + /*
> + * defer reset to if olpc_get_model() fails, it's quite a time eater
> + */
> + priv->i = olpc_get_model(psmouse);
> + if (!priv->i) {
> + psmouse_reset(psmouse);
> + priv->i = olpc_get_model(psmouse);
> + if (!priv->i)
> + return -1;
> + }
>
> mode = olpc_find_mode(psmouse);
> if (mode < 0)
>
--
Jim Gettys
One Laptop Per Child
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