From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753120AbaIAKBm (ORCPT ); Mon, 1 Sep 2014 06:01:42 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:48975 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752969AbaIAKBk (ORCPT ); Mon, 1 Sep 2014 06:01:40 -0400 X-AuditID: cbfee61b-f79f86d00000144c-fc-54044401e276 From: Bartlomiej Zolnierkiewicz To: Greg Kroah-Hartman Cc: Vivek Gautam , Felipe Balbi , Olof Johansson , Kukjin Kim , Kyungmin Park , "linux-samsung-soc@vger.kernel.org" , Linux USB Mailing List , "linux-kernel@vger.kernel.org" , Alan Stern Subject: Re: [PATCH] usb: dwc3: exynos: remove usb_phy_generic support Date: Mon, 01 Sep 2014 12:01:35 +0200 Message-id: <140959597.EmCWO5CWP9@amdc1032> User-Agent: KMail/4.8.4 (Linux/3.2.0-54-generic-pae; KDE/4.8.5; i686; ; ) In-reply-to: <20140829183304.GB9380@kroah.com> References: <2141307.zYQLjP6V6U@amdc1032> <2682311.psIh2sovYX@amdc1032> <20140829183304.GB9380@kroah.com> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset=us-ascii X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrHLMWRmVeSWpSXmKPExsVy+t9jQV0mF5YQg997WC0O3q+3aLtykN2i efF6NoveBVfZLM42vWG3uLxrDpvFjPP7mCwWLWtltjh1/TObxYTfF9gcuDz2z13D7nHlRBOr x+y7Pxg9+rasYvQ4fmM7k8fnTXIBbFFcNimpOZllqUX6dglcGVdePmMp2KJa8a79CmMD40WZ LkZODgkBE4l7H+cxQdhiEhfurWcDsYUEpjNKdC5x6WLkArJbmCRO7e1mBUmwCVhJTGxfxQhi iwgYS/SfncUOUsQssIJZ4tbEV2BFwgJuEt3XrwDZHBwsAqoSc/6Zg4R5BbQlbvfdYwGxRQU8 JXZsXwm2jFNAT6Lt81MWiMXZEqvXfGGGqBeU+DEZop5ZQF5i3/6prBC2lsT6nceZJjAKzEJS NgtJ2SwkZQsYmVcxiqYWJBcUJ6XnGukVJ+YWl+al6yXn525iBMfCM+kdjKsaLA4xCnAwKvHw PpjFHCLEmlhWXJl7iFGCg1lJhLfQkSVEiDclsbIqtSg/vqg0J7X4EKM0B4uSOO/BVutAIYH0 xJLU7NTUgtQimCwTB6dUAyOr6pnD156vN2kIaJFULwu5fcBf78mdI0uFHnyMjDw2/1ap+Vyn mztMppaJOUSy5q1IFmBcNfnw/lNvZzO7RisFcsr/qhJS5s+MkLI+qbJKVG4T2+MkrnxhjtqZ H5vZVZ5MCJB+P/twS3BuhqHSY5ErK4UUbn2QO9S3183BvUfl4FfpfVNko5RYijMSDbWYi4oT AapmV4aBAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Friday, August 29, 2014 11:33:04 AM Greg Kroah-Hartman wrote: > On Fri, Aug 29, 2014 at 11:02:52AM +0200, Bartlomiej Zolnierkiewicz wrote: > > On Thursday, August 28, 2014 12:29:52 PM Greg Kroah-Hartman wrote: > > > On Thu, Aug 28, 2014 at 08:11:04PM +0200, Bartlomiej Zolnierkiewicz wrote: > > > > > > > > [ added Alan and Greg to cc: ] > > > > > > > > Hi, > > > > > > > > On Wednesday, August 27, 2014 11:42:25 PM Vivek Gautam wrote: > > > > > Hi Baltlomiej, > > > > > > > > > > > > > > > On Wed, Aug 27, 2014 at 1:22 PM, Bartlomiej Zolnierkiewicz > > > > > wrote: > > > > > > dwc3 driver is using the new Exynos5 SoC series USB DRD PHY driver > > > > > > (PHY_EXYNOS5_USBDRD which selects GENERIC_PHY) as can be seen by > > > > > > looking at the following commits: > > > > > > > > > > > > 7a4cf0fde054 ("ARM: dts: Update DWC3 usb controller to use new > > > > > > phy driver for exynos5250") > > > > > > > > > > > > f070267b5fc1 ("ARM: dts: Enable support for DWC3 controller for > > > > > > exynos5420") > > > > > > > > > > > > Thus remove unused usb_phy_generic support from dwc3 Exynos glue > > > > > > layer. > > > > > > > > > > > > [ The code that is being removed is harmful in the context of > > > > > > multi_v7_defconfig and enabling "EHCI support for Samsung > > > > > > S5P/EXYNOS SoC Series" (USB_EHCI_EXYNOS) + "OHCI support for > > > > > > Samsung S5P/EXYNOS SoC Series" (USB_OHCI_EXYNOS) because "EHCI > > > > > > support for OMAP3 and later chips" (USB_EHCI_HCD_OMAP) selects > > > > > > "NOP USB Transceiver Driver" (NOP_USB_XCEIV). NOP USB driver > > > > > > attaches itself to usb_phy_generic platform devices created by > > > > > > dwc3 Exynos glue layer and later causes Exynos EHCI driver to > > > > > > fail probe and Exynos OHCI driver to hang on probe (as observed > > > > > > on Exynos5250 Arndale board). ] > > > > > > > > > > The issue with EHCI and OHCI on exynos platforms is that until now > > > > > they also request > > > > > usb-phy and only later if they don't find one, they go ahead and get a > > > > > 'phy' generic. > > > > > > > > > > Fortunately we missed this issue with exynos_defconfig, and as you rightly > > > > > mentioned with multi_v7_defconfig, the NOP_USB_XCEIV gets enabled and > > > > > EHCI and OHCI exynos get no-op usb-phy, which actually blocks EHCI/OHCI from > > > > > initializing the real PHYs. > > > > > > > > > > This issue is resolved with patches: > > > > > [PATCH v2 1/2] usb: host: ehci-exynos: Remove unnecessary usb-phy support > > > > > [PATCH v2 2/2] usb: host: ohci-exynos: Remove unnecessary usb-phy support > > > > > wherein we are completely removing the usb-phy support from ehci/ohci-exynos. > > > > > So with these patches we should not see the issue mentioned by you. > > > > > > > > Indeed, your patches fix the issue. > > > > > > > > Greg, could these two patches ([1] & [2]) get merged quickly, pretty please > > > > (they were already acked by Alan)? They are not a mere cleanups because > > > > they fix the actual problem with using multi_v7_defconfig which in turn has > > > > been blocking Olof's defconfig update patch [3] for quite some time now. > > > > Moreover these patches are limited to Exynos host drivers so they should be > > > > pretty safe when it comes to potential regressions. > > > > > > > > [1] http://www.spinics.net/lists/linux-usb/msg112294.html > > > > [2] http://www.spinics.net/lists/linux-usb/msg112293.html > > > > [3] http://www.spinics.net/lists/arm-kernel/msg349654.html > > > > > > merged for 3.18-rc1, or do you "need" them for 3.17-final? > > > > If it is not too much trouble please push them to 3.17-final. > > They don't meet the "regression or bugfix" rule at all, so I can't do > this, sorry. I'll queue them up for 3.18. These patches fix a real problem of boot hang when enabling Exynos USB host drivers and using ARM multiplatform config so IMHO they fall into bugfix category. > > > I already reverted one patch for exynos for 3.17-final that is sitting > > > in my tree to go to Linus soon as you all didn't seem to want it > > > anymore, so I'm getting really confused here... > > > > These two patches are a replacement for the one reverted and > > they just remove the old code instead of keeping it as fallback. > > This means that the reverted patch was not breaking anything and > > these two new patches could have been also done as incremental > > ones. Sorry for the confusion. > > As they came in too late for 3.17-rc1, they will have to wait for > 3.18-rc1. Okay.. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics