From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH] gpio: omap-gpio: add support for pm_runtime autosuspend Date: Mon, 29 Oct 2012 22:03:28 +0200 Message-ID: <20121029200328.GE30152@arwen.pp.htv.fi> References: <20121026114250.GA26342@arwen.pp.htv.fi> <1351257553-7896-1-git-send-email-tim.niemeyer@corscience.de> <508E266C.6090901@ti.com> <20121029080523.GC13657@arwen.pp.htv.fi> <508E3D09.9090802@ti.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="8vCeF2GUdMpe9ZbK" Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:59700 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760745Ab2J2UJX (ORCPT ); Mon, 29 Oct 2012 16:09:23 -0400 Content-Disposition: inline In-Reply-To: <508E3D09.9090802@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Santosh Shilimkar Cc: balbi@ti.com, Tim Niemeyer , Jon Hunter , Linux OMAP List --8vCeF2GUdMpe9ZbK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Oct 29, 2012 at 01:53:37PM +0530, Santosh Shilimkar wrote: > >>Just to expand a bit, Out of 6 GPIO banks, GPIO1 bank is in always ON > >>domain where as remaing 5 are in peripheral domain. Letting individual > >>banks idle allowed you let the clock domain idle than keeping all the > >>6 banks and hence respective clock/power domain in ON state. > >> > >>So the adding timeout might be reasonable but I am not sure about > >>the mod_usage change here. > > > >IMHO that whole mod_usage is broken. I remember sending a big series of > >patches getting rid of that long ago. I _did_ break a few things but > >just because of omap_gpio_prepare_for_idle() / > >omap_gpio_resume_from_idle() hackery to get GPIO suspended early enough. > > > Well so far I haven't seen/come across a patch/proposal which fixes it. fair point > >I still think mod_usage needs to go, so does > >omap_gpio_prepare_for_idle() and omap_gpio_resume_from_idle(). To me, it > >looks like that needs to be done on ->prepare()/->complete() callbacks > >of system suspend and the gpio driver needs to learn proper runtime > >suspend. > > > I am not saying it shouldn't go :-) > The $subject patch isn't fixing it correctly is what I said. >=20 > Don't get hung up on suspend case because thats the easiest > way to address it. The issue is with idle where GPIO can prevent > SOC idle if it isn't taken care. And since its just an IO, its not > easy to implement something like inactivity timer towards > autosupend. I don't see the relation here. Care to expand a bit ? > Co-processor also makes use of GPIO via syslink proxy and thats > make things even harder. that's supposed to be solved with hwspinlock, isn't it ? cheers --=20 balbi --8vCeF2GUdMpe9ZbK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQjuEQAAoJEIaOsuA1yqRERj0P/2v+uyt7V2wyd7WZKtJvFsba ebvRDOESJ5jvsyrogUmMDyius/Z/pb+wA9R//+K/2qlJz1bieyP4bs0XybN/OsbV 2f4nijhf8mBP08BMdwom7a3UwuzwOv6FIXFYxUao3K3mbAFFVrwbg9zTdmEqYcYa K7IUvizr7lSuDpvgkbHjLjppF25OU8TSALxSXQeAyOh5Zon7atKBVtJVLJuE9gFp 3VZVOG0rCugdc9UxzJKvOBeTQGXkQ5Hr0qtQi+esGIlgF0boR+M7R5X5ebaBF+z6 GlQU01c730zugmBohyjwupCF33v67ToJ1q78NJ58nXAhSulevneg8zCsKJObfv36 C0/ZUJMkFaeQoyZ7Z7CUbsGS7j6DfmfIL7k61pOxjFavoh6yb6OKyH854HWDf4ru zfrDv4FHzmUrXDVA7SpXlvskkWF9O4BwmyrR2bZ48BCuusuWRKF7IlofHUxv4MDI a4Fb3ue8YLxaz55bI7i9uaxaaIyB8FzVCBOOd/JC58RcO6syfuTlqn/LkLIJ75ix AK7H0i3zjlVhLIyp52KyA+PF3sSQXPgfzY8MvwZFkFf/w8/dPLuuvjFetu7Y257U yzeFBI3UcIQbKVn2EcwLGdz3LA0qsQDiDRZps/UD+WXwXKhFof+uqC6mSyYJVXNY KalTb2ZVCwzLQoe3jel+ =mlnT -----END PGP SIGNATURE----- --8vCeF2GUdMpe9ZbK--