Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754647AbbFBECB (ORCPT ); Tue, 2 Jun 2015 00:02:01 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:47391 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbbFBEBw (ORCPT ); Tue, 2 Jun 2015 00:01:52 -0400 Message-ID: <556D2A6E.4070802@ti.com> Date: Tue, 2 Jun 2015 07:00:46 +0300 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Mathias Nyman , Yingjoe Chen , CC: , Mark Rutland , , Sascha Hauer , , , Rob Herring , , Matthias Brugger , , Maxime Ripard Subject: Re: [PATCH 3/6] xhci: probe phy before add usb_hcd References: <1432727283-20303-1-git-send-email-chunfeng.yun@mediatek.com> <1432727283-20303-4-git-send-email-chunfeng.yun@mediatek.com> <20150527121843.GA8611@saruman.tx.rr.com> <1433170337.12128.18.camel@mtksdaap41> <556C7770.70506@intel.com> In-Reply-To: <556C7770.70506@intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2304 Lines: 66 Mathias. On 01/06/15 18:17, Mathias Nyman wrote: > On 01.06.2015 17:52, Yingjoe Chen wrote: >> On Wed, 2015-05-27 at 07:18 -0500, Felipe Balbi wrote: >>> On Wed, May 27, 2015 at 07:48:00PM +0800, chunfeng.yun@mediatek.com wrote: >>>> From: Chunfeng Yun >>>> >>>> find the phy driver before add primary usb_hcd to avoid acessing >>>> xHCI register which may hangup the system when the phy is not loaded >>>> yet and the related powers or clocks put in phy driver are not >>>> enabled. >>> >>> it seems like the same clock is needed by PHY and XHCI. This patch looks >>> incorrect. >> >> >> Hi, >> >> I agree that the driver should enable clock it used by itself and not >> depends on init order. This should be fixed. >> >> But in general, I think it make sense to only add hcd after all required >> resource are ready. At least it remove unnecessary calls to >> usb_add_hcd/usb_remove_hcd. Is it better if the commit message is >> changed to something like the below? >> >> Currently xhci_plat_probe() call usb_add_hcd before trying to init the >> phy. However if the phy is not ready at the moment, it have to remove >> the hcd and probe again later >> >> Change the init order so we only add hcd when all required resource are >> ready. >> > Hi > > Rogers Quadros patchseries that changes how HCDs are created and added for > xhci-plat was just sent forward. It first creates both HCDs, then adds them. > > Doesn't usb_add_hcd() as it's first task take care of the PHYs? > I'm hoping to remove that part completely from xhci-plat.c but haven't > looked into it properly yet. > usb_add_hcd() does if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) { struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0); ... if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) { struct phy *phy = phy_get(hcd->self.controller, "usb"); ... but xhci-plat.c does hcd->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); So there needs to be some alignment. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/