From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [RFT PATCH 1/3] usb: misc: usb3503: Fix HUB mode after bootloader initialization Date: Tue, 3 May 2016 13:00:22 -0500 Message-ID: <20160503180022.GA3008@rob-hp-laptop> References: <1461927591-7864-1-git-send-email-k.kozlowski@samsung.com> <1461927591-7864-2-git-send-email-k.kozlowski@samsung.com> <20160429113059.GX3217@sirena.org.uk> <57234BA2.6020304@samsung.com> <20160429164448.GY3217@sirena.org.uk> <57272298.50701@samsung.com> <20160502105501.GE6292@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160502105501.GE6292@sirena.org.uk> Sender: linux-samsung-soc-owner@vger.kernel.org To: Mark Brown Cc: Krzysztof Kozlowski , Kukjin Kim , Chanwoo Choi , Liam Girdwood , Greg Kroah-Hartman , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-usb@vger.kernel.org, linux.amoon@gmail.com, tjakobi@math.uni-bielefeld.de, m.szyprowski@samsung.com, hverkuil@xs4all.nl, Bartlomiej Zolnierkiewicz List-Id: devicetree@vger.kernel.org On Mon, May 02, 2016 at 11:55:01AM +0100, Mark Brown wrote: > On Mon, May 02, 2016 at 11:49:12AM +0200, Krzysztof Kozlowski wrote: > > > This VDD regulator supply actually is not a usb3503 USB HUB regulator > > supply... but a supply to the LAN attached to this HUB. Regulator off/on > > is needed for LAN to show up. The hub will show up with typical reset > > (which is also missing before my patchset btw). > > > The LAN, as a USB device, is auto-probed so it cannot take the regulator > > and play with it. The simplest idea I have is to add it as "external > > supply" to the parent: usb3503. > > This is common enough that that just isn't going to scale well I fear > without some generic handling, either walking child devices at the bus > level or at the device level with a pre-probe() callback to get the > device to power on. The latter is more appropriate to things like > Slimbus where the device is more likely to do active management at > runtime, it's not clear people are building USB devices like that. There's a new binding and support in -next (.../usb/usb-device.txt) for USB devices that should help here. Though, how to handle a hub on USB and I2C buses would need to be worked out. Rob