From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Thu, 19 Mar 2015 17:02:08 +0100 Subject: [PATCH v3 1/4] i2c: mux-pinctrl: Rework to honor disabled child nodes In-Reply-To: <550AEF9D.6090307@wwwdotorg.org> 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> Message-ID: <20150319160208.GF7657@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > >- /* 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 status */ > >+ if (!adap->dev.of_node || !of_device_is_available(adap->dev.of_node)) > > return; > > That feels a bit odd to me. For a regular non-mux I2C controller, that extra > 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 check > whether each bus node was disabled or not. That'd isolate the special case > into the place where it was relevant. ... 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? -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: