From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chunfeng Yun Subject: Re: [PATCH 3/6] usb: bdc: driver may fail to get USB PHY Date: Fri, 21 Jun 2019 13:39:39 +0800 Message-ID: <1561095579.32589.3.camel@mhfsdcap03> References: <1561064991-16874-1-git-send-email-alcooperx@gmail.com> <1561064991-16874-4-git-send-email-alcooperx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1561064991-16874-4-git-send-email-alcooperx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Al Cooper Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Luis Chamberlain , Mark Rutland , Rob Herring List-Id: devicetree@vger.kernel.org On Thu, 2019-06-20 at 17:09 -0400, Al Cooper wrote: > Initialization order is important for the USB PHY and the PHY clients. > The init order is based on the build order of the drivers in the > makefiles and the PHY drivers are built early to help with > dependencies, but the new SCMI based clock subsystem has the side > effect of making some additional drivers DEFER until the clock > is ready. This is causing the USB PHY driver to defer which is causing > some PHY clients to fail when they try to get the PHY. The fix is to have > the client driver return DEFER when it's "get phy" routine returns DEFER. > > Signed-off-by: Al Cooper > --- > drivers/usb/gadget/udc/bdc/bdc_core.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/gadget/udc/bdc/bdc_core.c b/drivers/usb/gadget/udc/bdc/bdc_core.c > index 11a43de6c1c6..c794890d785b 100644 > --- a/drivers/usb/gadget/udc/bdc/bdc_core.c > +++ b/drivers/usb/gadget/udc/bdc/bdc_core.c > @@ -543,9 +543,13 @@ static int bdc_probe(struct platform_device *pdev) > dev, dev->of_node, phy_num); > if (IS_ERR(bdc->phys[phy_num])) { > ret = PTR_ERR(bdc->phys[phy_num]); > + if (ret == -EPROBE_DEFER) { > + dev_dbg(bdc->dev, "DEFER, waiting for PHY\n"); why not disable clock here? when re-probe, will enable clock again. to me, no need check -EPROBE_DEFFER. > + return ret; > + } > dev_err(bdc->dev, > "BDC phy specified but not found:%d\n", ret); > - return ret; > + goto clk_cleanup; > } > } >