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From: "Éric Piel" <eric.piel@tremplin-utc.net>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Samu Onkalo <samu.p.onkalo@nokia.com>,
	Pavel Machek <pavel@ucw.cz>,
	lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org,
	Marcin Derlukiewicz <marcin@derlukiewicz.pl>
Subject: Re: [PATCH] lis3lv02d: provide means to disable polled input interface
Date: Fri, 09 Apr 2010 15:29:53 +0200	[thread overview]
Message-ID: <4BBF2BD1.5050107@tremplin-utc.net> (raw)
In-Reply-To: <alpine.LNX.2.00.1004091453530.8345@pobox.suse.cz>

On 09/04/10 14:56, Jiri Kosina wrote:
> lis3lv02d driver creates emulated joystick interface for events reported 
> by the sensor.
> Because of HW, this has to be implemented as polled input device, with
> 20Hz frequency.
> 
> This is reported to create 20% CPU usage increase (and proportionaly higher
> power consumption) just for the ipolldevd kernel thread (which is used
> to read the sensor).
> 
> As most users probably only use the freefall functionality of the driver
> and not the joystick interface, provide means for disabling the registration
> of joystick device altogether via module parameter.
> (I'd rather make it default to 0, but this will break backwards compatibility).
Are you saying there is a 20% CPU usage even when the joystick interface
is not open? This should not happen (and this is not happening on my
laptop). The polling should happen only when a userspace app opens the
joystick interface (like running neverball).

So I'd tend to think it's more due to a misconfiguration of the system
(like xserver using the joystick interface as a pointer device) or it's
a bug in the way we set up the polling. Could you investigate and let me
know?

Cheers,
Eric

WARNING: multiple messages have this Message-ID (diff)
From: "Éric Piel" <eric.piel@tremplin-utc.net>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Samu Onkalo <samu.p.onkalo@nokia.com>,
	Pavel Machek <pavel@ucw.cz>,
	lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org,
	Marcin Derlukiewicz <marcin@derlukiewicz.pl>
Subject: Re: [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled
Date: Fri, 09 Apr 2010 13:29:53 +0000	[thread overview]
Message-ID: <4BBF2BD1.5050107@tremplin-utc.net> (raw)
In-Reply-To: <alpine.LNX.2.00.1004091453530.8345@pobox.suse.cz>

On 09/04/10 14:56, Jiri Kosina wrote:
> lis3lv02d driver creates emulated joystick interface for events reported 
> by the sensor.
> Because of HW, this has to be implemented as polled input device, with
> 20Hz frequency.
> 
> This is reported to create 20% CPU usage increase (and proportionaly higher
> power consumption) just for the ipolldevd kernel thread (which is used
> to read the sensor).
> 
> As most users probably only use the freefall functionality of the driver
> and not the joystick interface, provide means for disabling the registration
> of joystick device altogether via module parameter.
> (I'd rather make it default to 0, but this will break backwards compatibility).
Are you saying there is a 20% CPU usage even when the joystick interface
is not open? This should not happen (and this is not happening on my
laptop). The polling should happen only when a userspace app opens the
joystick interface (like running neverball).

So I'd tend to think it's more due to a misconfiguration of the system
(like xserver using the joystick interface as a pointer device) or it's
a bug in the way we set up the polling. Could you investigate and let me
know?

Cheers,
Eric

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lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

  reply	other threads:[~2010-04-09 13:29 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-09 12:56 [PATCH] lis3lv02d: provide means to disable polled input interface Jiri Kosina
2010-04-09 12:56 ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Jiri Kosina
2010-04-09 13:29 ` Éric Piel [this message]
2010-04-09 13:29   ` Éric Piel
2010-04-09 13:32   ` [PATCH] lis3lv02d: provide means to disable polled input interface Jiri Kosina
2010-04-09 13:32     ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Jiri Kosina
2010-04-09 18:11     ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled input interface Jean Delvare
2010-04-09 18:11       ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Jean Delvare
2010-04-16 11:41     ` [PATCH] lis3lv02d: provide means to disable polled input interface Marcin Derlukiewicz
2010-04-16 11:41       ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Marcin Derlukiewicz
2010-04-16 12:00       ` [PATCH] lis3lv02d: provide means to disable polled input interface samu.p.onkalo
2010-04-16 12:00         ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled samu.p.onkalo
2010-04-16 12:13         ` [PATCH] lis3lv02d: provide means to disable polled input interface Marcin Derlukiewicz
2010-04-16 12:13           ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Marcin Derlukiewicz
2010-04-16 13:56           ` [PATCH] lis3lv02d: provide means to disable polled input interface Éric Piel
2010-04-16 13:56             ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Éric Piel
2010-04-16 14:26             ` [PATCH] lis3lv02d: provide means to disable polled input interface Marcin Derlukiewicz
2010-04-16 14:26               ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Marcin Derlukiewicz
2010-04-16 14:30               ` [PATCH] lis3lv02d: provide means to disable polled input interface Éric Piel
2010-04-16 14:30                 ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Éric Piel
2010-04-16 12:06       ` [PATCH] lis3lv02d: provide means to disable polled input interface Éric Piel
2010-04-16 12:06         ` [lm-sensors] [PATCH] lis3lv02d: provide means to disable polled Éric Piel
2010-04-09 21:41   ` [PATCH] lis3lv02d: provide means to disable polled input interface Frans Pop

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