From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] i2c-s3c2410: Add stub runtime power management Date: Mon, 13 Feb 2012 16:37:49 -0800 Message-ID: <20120214003748.GD11931@opensource.wolfsonmicro.com> References: <1327171600-5489-1-git-send-email-broonie@opensource.wolfsonmicro.com> <4F1C082D.2080005@gmail.com> <20120122152234.GA2915@opensource.wolfsonmicro.com> <4F1C45C6.1040003@gmail.com> <4F1C4BF4.5040409@gmail.com> <20120122213952.GA29022@opensource.wolfsonmicro.com> <20120213233139.GJ2999@freya.fluff.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zS7rBR6csb6tI2e1" Return-path: Content-Disposition: inline In-Reply-To: <20120213233139.GJ2999-RazCHl0VsYgkUSuvROHNpA@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ben Dooks Cc: Sylwester Nawrocki , Bill Gatliff , Wolfram Sang , Ben Dooks , linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: linux-pm@vger.kernel.org --zS7rBR6csb6tI2e1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 13, 2012 at 11:31:39PM +0000, Ben Dooks wrote: > On Sun, Jan 22, 2012 at 09:39:53PM +0000, Mark Brown wrote: > > TBH I think most of the devices for which people are running these days > > will be able to get some win from the system wide stuff - the WFI modes > > aren't exactly the latest thing in hardware terms, it's just been a long > > road to getting them supported. Infrastructure like Mark's PM QoS work > > and Raphael's PM domains work has really helped a lot here. > The WFI stuff's been around for ages, and is generally just the core that > is affected. The deep sleep options might be useful, so I don't see any > reason not to do this. I also approve that it might allow people to shut > down I2C units they're not using at the time to save power. On the more recent devices they've got wider effects if you configure the device to enter one of the lower power states on WFI - things will break quite badly if you enter even SLEEP mode on s3c64xx right now for example as we don't make sure things like the UARTs are quiesced enough. The power savings are nice, though. --zS7rBR6csb6tI2e1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPOazVAAoJEBus8iNuMP3djTIP/34ySicxBiw6abdAppgmuw/j /7BRNbYaumoLxfr2HsC/uTzCeGd6XrtkIMSJsc7uAyuG9TxZNRvg2hFcFYjtRXRu XrsHorpaZGPZjtTwMM0j/S4SsAhdL7OAqaJ7QCs12+PxTKaaQIHTrFvCU+1pOmWk 2QVOxzJgPz35mrluKjCANt4+K3/vFf2dxt7/fX2jw3k3/aTk7upbdPgu3lXaELfv CNLR8uyNGQb3JJGCpfSBBvb0OpnWpXJYrYBQXD0i/ygOL6z2c+mYtXVHtmyfNsl6 F2cct9hHu3piEnCtHFyfwRrvP9LyYU5cVBHOMJxOn77+gvLJC0r5XFFjbFDJI/LT WsMgID6R5oZvF4sOQIiJUG8BF195ZPhP9++HemPIaHWvzDKVIxRsxd1YKGwP5SMg 1zHe9wJuxAOXNrU8DOCBKZEcqaztzceLpPY5Xq8O40Zz2Jqh3H3Gf6Ki/1TYyU+K nkAyxnaoSbGMeQ6QBKZbvPf0lNiU/UnS56wFy6PiZkfzpnA6WDGixozsba80TVJe CVGQHm+N0tWfbrp8EI5SEjm82A7H5Azj1w0NzyQdCa8riClB+78aic7QIFA0VLSX 4WDr/SNq+dsmNToNZa06hDJifDdFMuA4iqqOo1rh2LxkoNOzpk5nPIynWVcPCDEI Wbm7KFccTNE0u7DaFG8G =0Fe3 -----END PGP SIGNATURE----- --zS7rBR6csb6tI2e1--