From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754445AbaILMDm (ORCPT ); Fri, 12 Sep 2014 08:03:42 -0400 Received: from top.free-electrons.com ([176.31.233.9]:54238 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754374AbaILMDl (ORCPT ); Fri, 12 Sep 2014 08:03:41 -0400 Date: Fri, 12 Sep 2014 14:03:36 +0200 From: Antoine Tenart To: Peter Chen Cc: Antoine Tenart , "balbi@ti.com" , "gregkh@linuxfoundation.org" , "kishon@ti.com" , "stern@rowland.harvard.edu" , "sergei.shtylyov@cogentembedded.com" , "yoshihiro.shimoda.uh@renesas.com" , "alexandre.belloni@free-electrons.com" , "thomas.petazzoni@free-electrons.com" , "zmxu@marvell.com" , "jszhang@marvell.com" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v4 9/9] usb: chipidea: add support to the generic PHY framework in ChipIdea Message-ID: <20140912120336.GD18774@kwain> References: <1409730040-14200-1-git-send-email-antoine.tenart@free-electrons.com> <1409730040-14200-10-git-send-email-antoine.tenart@free-electrons.com> <20140911005446.GD3609@peterchendt> <20140911154222.GB11275@kwain> <20140912082125.GA18774@kwain> <20140912092711.GA2463@peterchendt> <20140912093550.GC18774@kwain> <20140912102828.GB2463@peterchendt> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140912102828.GB2463@peterchendt> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 12, 2014 at 06:28:29PM +0800, Peter Chen wrote: > On Fri, Sep 12, 2014 at 11:35:50AM +0200, Antoine Tenart wrote: > > On Fri, Sep 12, 2014 at 05:27:13PM +0800, Peter Chen wrote: > > > On Fri, Sep 12, 2014 at 10:21:25AM +0200, Antoine Tenart wrote: > > > > Peter, > > > > > > > > On Fri, Sep 12, 2014 at 01:10:33AM +0000, Peter Chen wrote: > > > > > > On Thu, Sep 11, 2014 at 08:54:47AM +0800, Peter Chen wrote: > > > > > > > On Wed, Sep 03, 2014 at 09:40:40AM +0200, Antoine Tenart wrote: > > > > > > > > @@ -595,23 +639,27 @@ static int ci_hdrc_probe(struct platform_device > > > > > > *pdev) > > > > > > > > return -ENODEV; > > > > > > > > } > > > > > > > > > > > > > > > > - if (ci->platdata->usb_phy) > > > > > > > > + if (ci->platdata->phy) > > > > > > > > + ci->phy = ci->platdata->phy; > > > > > > > > + else if (ci->platdata->usb_phy) > > > > > > > > ci->usb_phy = ci->platdata->usb_phy; > > > > > > > > else > > > > > > > > - ci->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2); > > > > > > > > + ci->phy = devm_phy_get(dev, "usb-phy"); > > > > > > > > > > > > > > > > - if (IS_ERR(ci->usb_phy)) { > > > > > > > > - ret = PTR_ERR(ci->usb_phy); > > > > > > > > + if (IS_ERR(ci->phy) || (ci->phy == NULL && ci->usb_phy == NULL)) { > > > > > > > > /* > > > > > > > > * if -ENXIO is returned, it means PHY layer wasn't > > > > > > > > * enabled, so it makes no sense to return -EPROBE_DEFER > > > > > > > > * in that case, since no PHY driver will ever probe. > > > > > > > > */ > > > > > > > > - if (ret == -ENXIO) > > > > > > > > - return ret; > > > > > > > > + if (PTR_ERR(ci->phy) == -ENXIO) > > > > > > > > + return -ENXIO; > > > > > > > > > > > > > > > > - dev_err(dev, "no usb2 phy configured\n"); > > > > > > > > - return -EPROBE_DEFER; > > > > > > > > + ci->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2); > > > > > > > > + if (IS_ERR(ci->usb_phy)) { > > > > > > > > + dev_err(dev, "no usb2 phy configured\n"); > > > > > > > > + return -EPROBE_DEFER; > > > > > > > > + } > > > > > > > > } > > > > > > > > > > > > > > Sorry, I can't accept this change, why devm_usb_get_phy(dev, > > > > > > > USB_PHY_TYPE_USB2) is put at error path? Since current get PHY > > > > > > > operation is a little complicated, we may have a dedicate function to do it, > > > > > > dwc3 driver is a good example. > > > > > > > > > > > > It's not the error path, it's the case when there is no PHY from the generic PHY > > > > > > framework available. Getting an USB PHY is a fallback solution. > > > > > > > > > > > > I agree we can move this to a dedicated function. But even if doing so, we'll > > > > > > have to test ci->phy first. > > > > > > > > > > > > Or do you have something else in mind? > > > > > > > > > > > > > > > > I still want devm_usb_get_phy(dev, USB_PHY_TYPE_USB2) to be called at the same place > > > > > like generic_phy, not in later error path, in error path, we only handle error. > > > > > > > > Would this fit you? > > > > > > > > if (ci->platdata->phy) > > > > ci->phy = ci->platdata->phy; > > > > else if (ci->platdata->usb_phy) > > > > ci->usb_phy = ci->platdata->usb_phy; > > > > > > > > if (ci->phy == NULL && ci->usb_phy == NULL) { > > > > > > You should use else if here. > > > > Yes, sure. > > > > > > > > > ci->phy = devm_phy_get(dev, "usb-phy"); > > > > ci->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2); > > > > > > > > /* if both generic PHY and USB PHY layers aren't enabled */ > > > > if (PTR_ERR(ci->phy) == -ENOSYS && PTR_ERR(ci->usb_phy) == -ENXIO) > > > > return -ENXIO; > > > > > > > > if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy)) > > > > return -EPROBE_DEFER; > > > > > > > > /* if an usb_phy is available, but no phy is there */ > > > > if (PTR_ERR(ci->phy) == -ENODEV) > > > > ci->phy = NULL; > > > if (ci->phy) > > > ci->usb_phy = NULL; > > > if (ci->usb_phy) > > > ci->phy = NULL; > > > > > > How about above? > > > > When no PHY or USB PHY is found, -ENODEV is returned. Doing the above > > would always end up having ci->phy and ci->usb_phy being NULL. > > When we try to get generic phy, if -ENODEV is returned, the ci->usb_phy > should not be NULL, otherwise, your the second condition will return > -EPROBE_DEFER, it means when the code goes here, there must be one PHY > is found. We first call devm_phy_get() and devm_usb_get_phy(), ci->phy and ci->usb_phy can't be NULL after this. Then the "if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy))" ensure at least one of them is a valid PHY. I don't see the problem here. Am I missing something? > > > > > We could have: > > > > if (IS_ERR(ci->phy)) > > ci->phy = NULL; > > else if (IS_ERR(ci->usb_phy)) > > ci->usb_phy = NULL; > > Antoine -- Antoine Ténart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com