From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: PM regression with LED changes in next-20161109 Date: Fri, 11 Nov 2016 23:06:32 +0100 Message-ID: <20161111220631.GA10983@amd> References: <28234714-3994-6747-9cf8-1ff0b3257f7a@gmail.com> <5bd5333e-0dbb-6333-0a48-ca4d3a990f9c@samsung.com> <20161110162925.GA28832@amd> <20161110175537.GF27724@atomide.com> <20161110202910.GE28832@amd> <80b645e7-c3fa-8001-d9b1-c3c8c40394fd@gmail.com> <20161111120114.GA1076@amd> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="mYCpIKhGyMATD0i+" Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:40539 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935747AbcKKWGf (ORCPT ); Fri, 11 Nov 2016 17:06:35 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Jacek Anaszewski Cc: Tony Lindgren , Jacek Anaszewski , Hans de Goede , linux-leds@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Darren Hart --mYCpIKhGyMATD0i+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > >Hmm. So userland can read the LED state, and it can get _some_ value > >back, but it can not know if it is current state or not. > > > >I don't think that's a good interface. I see it is from 2008... is > >someone using it? Maybe it is too late for revert. >=20 > I can imagine it being used in flash LED use case. E.g. one > could use oneshot trigger to trigger flash strobe, and then > he could periodically read brightness file to check, for whatever > reason, whether the flash is strobing. I'm pretty sure nobody does that for flah strobe. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --mYCpIKhGyMATD0i+ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlgmQOcACgkQMOfwapXb+vI8sACeImsqzf26l0r7vdzBe5nM1XM2 /BcAnR2H22RgnQXbmAJWYWWbovIgjohc =P3Px -----END PGP SIGNATURE----- --mYCpIKhGyMATD0i+-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Fri, 11 Nov 2016 23:06:32 +0100 Subject: PM regression with LED changes in next-20161109 In-Reply-To: References: <28234714-3994-6747-9cf8-1ff0b3257f7a@gmail.com> <5bd5333e-0dbb-6333-0a48-ca4d3a990f9c@samsung.com> <20161110162925.GA28832@amd> <20161110175537.GF27724@atomide.com> <20161110202910.GE28832@amd> <80b645e7-c3fa-8001-d9b1-c3c8c40394fd@gmail.com> <20161111120114.GA1076@amd> Message-ID: <20161111220631.GA10983@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi! > >Hmm. So userland can read the LED state, and it can get _some_ value > >back, but it can not know if it is current state or not. > > > >I don't think that's a good interface. I see it is from 2008... is > >someone using it? Maybe it is too late for revert. > > I can imagine it being used in flash LED use case. E.g. one > could use oneshot trigger to trigger flash strobe, and then > he could periodically read brightness file to check, for whatever > reason, whether the flash is strobing. I'm pretty sure nobody does that for flah strobe. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: