From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754347AbbJGO1G (ORCPT ); Wed, 7 Oct 2015 10:27:06 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:8716 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753982AbbJGO1E (ORCPT ); Wed, 7 Oct 2015 10:27:04 -0400 X-AuditID: cbfec7f4-f79c56d0000012ee-20-56152bb4d72c Subject: Re: [RFT 0/3] usb: usb3503: Fix probing on Arndale board (missing phy) To: Krzysztof Kozlowski , Greg Kroah-Hartman , Peter Chen , Ben Gamari , Wolfram Sang , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Kukjin Kim , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org References: <1444177807-15524-1-git-send-email-k.kozlowski@samsung.com> Cc: Kevin Hilman , Arnd Bergmann , riku.voipio@linaro.org From: Marek Szyprowski Message-id: <56152BB2.4020202@samsung.com> Date: Wed, 07 Oct 2015 16:26:58 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-version: 1.0 In-reply-to: <1444177807-15524-1-git-send-email-k.kozlowski@samsung.com> Content-type: text/plain; charset=utf-8; format=flowed Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprGIsWRmVeSWpSXmKPExsVy+t/xy7pbtEXDDF61y1j8nXSM3WLW/Lss FvOPnGO1aF68ns3i9QtDi/7Hr5ktnm5+zGSx6fE1VovLu+awWcw4v4/JYtGyVmaLY7P/Mll0 netnslh5YhazA5/H71+TGD3+He5n8ti0qpPN4861PWwe++euYffYvKTeo2/LKkaPM7+dPU6e esLi8XmTXABXFJdNSmpOZllqkb5dAlfG6bmH2Qru8lacvzWPtYGxhbuLkZNDQsBE4sbRHYwQ tpjEhXvr2boYuTiEBJYySuw+P4MdwnnOKDF5zhZWkCphAX+JGUtPMYMkRASmM0vcmbmMGSQh JOAuseRlDxuIzSwQJ3F7xz+wOJuAoUTX2y6wOK+AlsTToyfBBrEIqEpMaX/HAmKLCsRIvN+0 ihGiRlDix+R7YHFOAQ+JjX17WCFmmkl8eXkYypaX2LzmLfMERoFZSFpmISmbhaRsASPzKkbR 1NLkguKk9FxDveLE3OLSvHS95PzcTYyQ2Pqyg3HxMatDjAIcjEo8vD+MRcKEWBPLiitzDzFK cDArifA2fgcK8aYkVlalFuXHF5XmpBYfYpTmYFES5527632IkEB6YklqdmpqQWoRTJaJg1Oq gXGVCe/J16WVi4IY2ux+HaiKqLv6L9Li7Lv1569MuPqv+SKHXMTrHhHmavbbKyokwvXZUhsP 2fTJ7NM7W37se1O8l8Ea88DpKSfn3XjIYqSydX6d5eKuk8XmooZCcnKfufxbzZlOOK1pcBGx E43X0HxbNu/l1uVXF2ir8eoE7U/VTony6Hk8U4mlOCPRUIu5qDgRADUUXzWpAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 2015-10-07 02:30, Krzysztof Kozlowski wrote: > Introduction > ============ > This patchset tries to fix probing of usb3503 on Arndale board > if the Samsung PHY driver is probed later (or built as a module). > > *The patchset was not tested on Arndale board.* > I don't have that board. Please test it and say if the usb3503 deferred probe > works fine and the issue is solved. > > The patchset was tested on Odroid U3 board (which is different!) > in a simulated environment. It is not sufficient testing. > > > Difference > ========== > The usb3503 device driver can be used as a I2C device (on Odroid U3) > or as a platform device connected through phy (on Arndale). In the second > case the necessary phy reference has to be obtained and enabled. > > For some details please look also at thread [0][1]. > > [0] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/348524.html > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/348875.html > I'm not sure that this is the correct approach. usb3503 chip is simply connected to Exynos USB2 phy, so it visible on the USB bus. The real driver that controls USB2 PHY is Exynos EHCI driver and USB3503 should not mess around it. In my opinion all that is needed in case of Arndale board is forcing reset of usb3503 chip after successful EHCI and USB2 PHY initialization (for some reason initialization of usb3503 chip must be done after usb host initialization). However I have no idea which driver should trigger this reset. Right now I didn't find any good solution for additional control for devices which are on autoprobed bus like usb. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland