From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v2 10/10] usb: chipidea: tegra: Add USB_TEGRA_PHY module to driver's dependencies Date: Thu, 2 Jan 2020 18:17:47 +0300 Message-ID: References: <20191220015238.9228-1-digetx@gmail.com> <20191220015238.9228-11-digetx@gmail.com> <20191220035650.GC19921@b29397-desktop> <20191223213234.GA28786@qmqm.qmqm.pl> <7174833f-8325-7fb4-d190-78ba4bed0cbb@gmail.com> <20191230210259.GD24135@qmqm.qmqm.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20191230210259.GD24135@qmqm.qmqm.pl> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Cc: Peter Chen , Rob Herring , Greg Kroah-Hartman , Thierry Reding , Jonathan Hunter , Felipe Balbi , "devicetree@vger.kernel.org" , "linux-usb@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: linux-tegra@vger.kernel.org 31.12.2019 00:02, Michał Mirosław пишет: > On Tue, Dec 24, 2019 at 07:21:05AM +0300, Dmitry Osipenko wrote: >> 24.12.2019 00:32, Michał Mirosław пишет: >>> On Fri, Dec 20, 2019 at 07:31:08AM +0300, Dmitry Osipenko wrote: >>>> 20.12.2019 06:56, Peter Chen пишет: >>>>> On 19-12-20 04:52:38, Dmitry Osipenko wrote: >>> [...] >>>>>> --- a/drivers/usb/chipidea/ci_hdrc_tegra.c >>>>>> +++ b/drivers/usb/chipidea/ci_hdrc_tegra.c >>>>>> @@ -53,6 +53,12 @@ static int tegra_udc_probe(struct platform_device *pdev) >>>>>> struct tegra_udc *udc; >>>>>> int err; >>>>>> >>>>>> + if (IS_MODULE(CONFIG_USB_TEGRA_PHY)) { >>>>>> + err = request_module("phy_tegra_usb"); >>>>>> + if (err) >>>>>> + return err; >>>>>> + } >>>>>> + >>>>> >>>>> Why you do this dependency, if this controller driver can't >>>>> get USB PHY, it should return error. What's the return value >>>>> after calling below: >>>>> >>>>> udc->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0); >>>> >>>> It returns -EPROBE_DEFER when phy_tegra_usb isn't loaded. >>> >>> How are other driver modules autoloaded? Isn't there an appropriate >>> MODALIAS or MODULE_DEVICE_TABLE in there? >> >> Hello Michał, >> >> The phy_tegra_usb module is fine by itself, it's getting autoloaded. >> >> The problem is that ci_hdrc_tegra module depends on the phy_tegra_usb >> module and thus the PHY module should be loaded before the CI module, >> otherwise CI driver fails with the EPROBE_DEFER. > > Why, then, is CI driver not being probed again after PHY driver loads? > EPROBE_DEFER is what should cause driver core to re-probe a device after > other devices appear (PHY in this case). CI driver is getting re-probed just fine if PHY's driver module is loaded manually after loading the CI's module. This patch removes this necessity to manually load PHY's module. This is just a minor convenience change that brings the CI's driver loading behaviour on par with the behaviour of loading Tegra's EHCI driver module.