From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: twl4030_charger: need changes to get probed? Date: Mon, 9 Mar 2015 11:06:53 +1100 Message-ID: <20150309110653.7532613c@notabene.brown> References: <20150224043341.4243.23291.stgit@notabene.brown> <20150224043352.4243.11227.stgit@notabene.brown> <20150302210926.GP13270@amd> <20150305173350.50502b95@notabene.brown> <20150306212417.GA24169@amd> <20150307210102.GL5233@earth> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/t8viym4Ys3iYI07D4d0NOPc"; protocol="application/pgp-signature" Return-path: Received: from cantor2.suse.de ([195.135.220.15]:60906 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751738AbbCIAHH (ORCPT ); Sun, 8 Mar 2015 20:07:07 -0400 In-Reply-To: <20150307210102.GL5233@earth> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Sebastian Reichel Cc: Pavel Machek , pali.rohar@gmail.com, kernel list , linux-arm-kernel , linux-omap@vger.kernel.org, tony@atomide.com, khilman@kernel.org, aaro.koskinen@iki.fi, ivo.g.dimitrov.75@gmail.com, patrikbachan@gmail.com, Samuel Ortiz , Lee Jones , Dmitry Eremin-Solenikov , David Woodhouse , GTA04 owners , linux-pm@vger.kernel.org --Sig_/t8viym4Ys3iYI07D4d0NOPc Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sat, 7 Mar 2015 22:01:02 +0100 Sebastian Reichel wrote: > Hi, >=20 > On Fri, Mar 06, 2015 at 10:24:17PM +0100, Pavel Machek wrote: > > According to n900 dts, twl4030-bci (aka charger) should be > > included. >=20 > its part of twl, but not used on N900 afaik. >=20 > > (But it does not seem to do anything useful on n900. I was hoping for > > measurement of input voltage, but .. no.) >=20 > check for rx51-battery. >=20 > > Any ideas why the patch below is needed? >=20 > platform_driver_probe() does not support deferred probing. >=20 > Neil, can you take this patch into your series for the next round? I could, but I do wonder if it is the right thing to do. Shouldn't we fix platform_driver_probe() to support deferred probing. As I understand it, it refused to retry a probe if there is an error, and t= he comments suggest that such retrying is avoided because it would be a waste of time: /* * Prevent driver from requesting probe deferral to avoid further * futile probe attempts. */ In this case, it isn't futile. Earlier there is a comment saying: * Use this instead of platform_driver_register() when you know the device * is not hotpluggable and has already been registered, and you want to * remove its run-once probe() infrastructure from memory after the driver * has bound to the device. I presume all this applies. I assume that the only problem is a probe-order thing. So maybe we should fix platform_driver_probe() to do the right thing with -EPROBEDEFER?? Trouble is, I really don't understand the point or mechanism for platform_driver_probe(), so I cannot suggest anything. But I have been annoyed before that platform_driver_probe doesn't cope with EPROBEDEFER, so I would like it fixed. NeilBrown --Sig_/t8viym4Ys3iYI07D4d0NOPc Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUBVPzkHTnsnt1WYoG5AQKwHA//d5aOUNOlfZ59C9EtQGz1zSn+mpIsXjz0 MHcL7ZbBSfBxd8PLDBUpb/JRL/SelK5vFqOo2zmXvgqG/ANyDSo3vING8UU0kK2w WiTQzOKJ5JPfcW4jAPo1TMbE8C7iGttB1/Z0jOEe6BlZiDYpobWYYKV7wtK3dVPl c+Gdc1tY1s2v4+zoSe4t5gjZdBEsbS0Z2+4Y1ldkQ5Jx6dZyR9bThe/Orp1rJz3q FgNuvxrtf27BJEHGhZ9+gucK/thxHqilVXqTjj2EBAPFnnIDftuRCzEnck/ukCFp rvtGBHuNyAP8bQJYAs1/fObFlDkIdu4OqJE5sKWT0hhirx6D6EpMzsnfiCFRy4DG ajmhXEJQ1sKo0PFoJE82W3zXrgAoMGefuy8+oeagToQG8WfHI3RuqDVhEijg3Rj2 t131LOi3p2M4KlirhhBO3P9EXUvfPBtIOIo6Y1y2clxR/cIV5P1QSpTiuAm0G9Qt WvgrySckYYEv7naTF0wB9E3jr/7zV4qDlcloh50v0gqZlWIyvD24IFR0/NT89ByG tOKRs51XQ4fGphETeztoTX23N0OCd9+rY4uH4Sln34de6U24CVhlZQ9MEF/aZ0zh s3tK/ppkWEtWC4QgswqRTvXmER+5aRvUivkHOKcW8DbA3r+oHhNZmB03XOr7rnpY /K5p1mS9J+8= =4dn5 -----END PGP SIGNATURE----- --Sig_/t8viym4Ys3iYI07D4d0NOPc--