From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:35331 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932195AbcCOWH1 (ORCPT ); Tue, 15 Mar 2016 18:07:27 -0400 Subject: Re: [PATCH 2/2] iio: mma8452: use runtime pm instead of device specific autosleep To: Martin Kepplinger , knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net References: <1457954789-4885-1-git-send-email-martink@posteo.de> <1457954789-4885-2-git-send-email-martink@posteo.de> Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org From: Jonathan Cameron Message-ID: <56E8879D.4050409@kernel.org> Date: Tue, 15 Mar 2016 22:07:25 +0000 MIME-Version: 1.0 In-Reply-To: <1457954789-4885-2-git-send-email-martink@posteo.de> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 14/03/16 11:26, Martin Kepplinger wrote: > What is this autosleep? > ----------------------- > It slows down the device after x seconds of inactivity. The thing is, we have > really achieved almost the same by runtime pm. > > differnces are: > > autosleep > * uses more power during inactivity > * the first read after inactivity slightly faster > * complicated to understand for the user > * no documented sysfs interface (afaik) > * complicated to read and maintain > > runtime pm > * already merged in mma8452 > * uses less power during inactivity > * first read after inactivity slower > * easy to use. well documented. > * easy to maintain and understand > > The two approaches solve the same problem. runtime pm has more advantages > than autosleep and comes quite close to it's behaviour anyways. As I see it, > autosleep, even if somehow supported, would never be used anyways. > > So resolve this issue by "ignoring" autosleep. > > Signed-off-by: Martin Kepplinger > Reviewed-by: Martina Kepplinger A good detailed explanation + to be cynical, if anyone actually wants to implement it and provide numbers showing it is the best thing since sliced bread - the absence of a comment about it not being done isn't going to stop them! Applied, thanks, Jonathan > --- > drivers/iio/accel/mma8452.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c > index d0eeba0..375e45f 100644 > --- a/drivers/iio/accel/mma8452.c > +++ b/drivers/iio/accel/mma8452.c > @@ -17,7 +17,7 @@ > * > * 7-bit I2C slave address 0x1c/0x1d (pin selectable) > * > - * TODO: orientation events, autosleep > + * TODO: orientation events > */ > > #include >