From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH v3 1/4] i2c: mux-pinctrl: Rework to honor disabled child nodes Date: Thu, 19 Mar 2015 17:02:08 +0100 Message-ID: <20150319160208.GF7657@katana> References: <1425039885-5137-2-git-send-email-sebastian.hesselbarth@gmail.com> <1425903665-19343-1-git-send-email-sebastian.hesselbarth@gmail.com> <20150318123012.GA3580@katana> <55097C46.9010605@gmail.com> <20150318140037.GE3580@katana> <550A05E5.3050100@gmail.com> <20150319100944.GA914@katana> <550AEF9D.6090307@wwwdotorg.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="rWhLK7VZz0iBluhq" Return-path: Content-Disposition: inline In-Reply-To: <550AEF9D.6090307-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Sebastian Hesselbarth , Jason Cooper , Andrew Lunn , Gregory Clement , Gabriel Dobato , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --rWhLK7VZz0iBluhq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > >- /* Only register child devices if the adapter has a node pointer set */ > >- if (!adap->dev.of_node) > >+ /* Only register childs if adapter has a node pointer with enabled sta= tus */ > >+ if (!adap->dev.of_node || !of_device_is_available(adap->dev.of_node)) > > return; >=20 > That feels a bit odd to me. For a regular non-mux I2C controller, that ex= tra > case would never trigger if the controller node was disabled, since the > device core would never probe the controller device itself. So, we'd end = up > with inconsistent paths through the I2C core for regular controllers and > muxes. I first thought the no-op for the non-mux case wouldn't hurt, but I agree about the consistent code path. I mentioned in my previous mail that i2c-mux might be a better place for this... > Perhaps better would be to have a mux-specific function to iterate over a > mux's child nodes and instantiate buses for those. That function would ch= eck > whether each bus node was disabled or not. That'd isolate the special case > into the place where it was relevant. =2E.. so I wonder what you think about putting the of_device_is_available() check into i2c_add_mux_adapter() once the reg-property and chan_id have been matched? --rWhLK7VZz0iBluhq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVCvMAAAoJEBQN5MwUoCm2IWoP/AhjW9p5jR9fvBaBn48Y44VU P2X56TrUHkyrtidzzi9fXjRIY2hSeZcUZR1ZI3opkbTwI8kazHWlsu5fHBTgwehz d+EejLQ9X7v1//oQSJiucizPm+dkKSjcPhDc4TMIwkSfNQeJgTcd9wH7aqbNIC86 srgCjOLbiSd380+3fWDzicOLGGvVp1sclz3F6Rwjpb+1cuZV1HWbgk4Jo7jENATr RObnm7pDmkglEQTHc4cS1I/P3aqAURKitn7y414hB5NHfxEe4EEp9s/69YzjAUH7 hQc2XwXKkQAQRA7ka5IjLFnIAOJfhmjaQtVOURdOY/bpgRnpesVV28b3Z6QlzhkU bi3k/HdOT4TWJWzr2XRaO9YAGRFyUXePO55ESnZio9TGzGqxoxCzH3UXMcmpXul/ iWAkKcQjW3poUTjc++5tqZEgHk9dgMR0Dh08EBTOhf6/4QtygbFFm781BP9KUlIM tXdgB0FcG5Er5Dk9WDIlvqdghd2Pntv66I1yGlnYxMmJnqTCUepwD7J9l7ycHrRM AkWQem3SYCkbHoKsKqlTnuHkHeB0feSjepGCtwvO6w2cJcV4fuMoj+GXjApG6rD1 GxNMnqdcqRcT1S234XIPAzmNQcF0K8PNX+I4h9/m4aLoj0ITFzgfMEJaCwsQU54D QXqWr3vg82BYQ9cc0yFd =gJDw -----END PGP SIGNATURE----- --rWhLK7VZz0iBluhq--