From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE232C43460 for ; Fri, 9 Apr 2021 14:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96646600D1 for ; Fri, 9 Apr 2021 14:59:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234050AbhDIPAC (ORCPT ); Fri, 9 Apr 2021 11:00:02 -0400 Received: from netrider.rowland.org ([192.131.102.5]:59203 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S233908AbhDIO7z (ORCPT ); Fri, 9 Apr 2021 10:59:55 -0400 Received: (qmail 1333912 invoked by uid 1000); 9 Apr 2021 10:59:41 -0400 Date: Fri, 9 Apr 2021 10:59:41 -0400 From: Alan Stern To: Longfang Liu Cc: gregkh@linuxfoundation.org, mathias.nyman@intel.com, liudongdong3@huawei.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kong.kongxinwei@hisilicon.com, yisen.zhuang@huawei.com Subject: Re: [PATCH v4] USB:ehci:fix Kunpeng920 ehci hardware problem Message-ID: <20210409145941.GA1333284@rowland.harvard.edu> References: <1617958081-17999-1-git-send-email-liulongfang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1617958081-17999-1-git-send-email-liulongfang@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 09, 2021 at 04:48:01PM +0800, Longfang Liu wrote: > Kunpeng920's EHCI controller does not have SBRN register. > Reading the SBRN register when the controller driver is > initialized will get 0. > > When rebooting the EHCI driver, ehci_shutdown() will be called. > if the sbrn flag is 0, ehci_shutdown() will return directly. > The sbrn flag being 0 will cause the EHCI interrupt signal to > not be turned off after reboot. this interrupt that is not closed > will cause an exception to the device sharing the interrupt. > > Therefore, the EHCI controller of Kunpeng920 needs to skip > the read operation of the SBRN register. > > Signed-off-by: Longfang Liu > --- Acked-by: Alan Stern > Changes in v4: > - Modify the code implementation. > > Changes in v3: > - Fix some code style issues. > - Update struct name. > > Changes in v2: > - Fix some code style issues. > - Update function name. > > drivers/usb/host/ehci-pci.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c > index 3c3820a..237a346 100644 > --- a/drivers/usb/host/ehci-pci.c > +++ b/drivers/usb/host/ehci-pci.c > @@ -291,6 +291,9 @@ static int ehci_pci_setup(struct usb_hcd *hcd) > if (pdev->vendor == PCI_VENDOR_ID_STMICRO > && pdev->device == PCI_DEVICE_ID_STMICRO_USB_HOST) > ; /* ConneXT has no sbrn register */ > + else if (pdev->vendor == PCI_VENDOR_ID_HUAWEI > + && pdev->device == 0xa239) > + ; /* HUAWEI Kunpeng920 USB EHCI has no sbrn register */ > else > pci_read_config_byte(pdev, 0x60, &ehci->sbrn); > > -- > 2.8.1 >