From patchwork Mon Jun 8 03:46:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: liulongfang X-Patchwork-Id: 11592449 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2CB22912 for ; Mon, 8 Jun 2020 03:47:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17F532067B for ; Mon, 8 Jun 2020 03:47:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728782AbgFHDr3 (ORCPT ); Sun, 7 Jun 2020 23:47:29 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5865 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728763AbgFHDr3 (ORCPT ); Sun, 7 Jun 2020 23:47:29 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 9F835F4F95FB4B424CE4; Mon, 8 Jun 2020 11:47:26 +0800 (CST) Received: from huawei.com (10.67.165.24) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.487.0; Mon, 8 Jun 2020 11:47:20 +0800 From: Longfang Liu To: CC: , , , Subject: [PATCH v3] USB: ehci: reopen solution for Synopsys HC bug Date: Mon, 8 Jun 2020 11:46:59 +0800 Message-ID: <1591588019-44284-1-git-send-email-liulongfang@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 X-Originating-IP: [10.67.165.24] X-CFilter-Loop: Reflected Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org A Synopsys USB2.0 core used in Huawei Kunpeng920 SoC has a bug which might cause the host controller not issuing ping. Bug description: After indicating an Interrupt on Async Advance, the software uses the doorbell mechanism to delete the Next Link queue head of the last executed queue head. At this time, the host controller still references the removed queue head(the queue head is NULL). NULL reference causes the host controller to lose the USB device. Solution: After deleting the Next Link queue head, when has_synopsys_hc_bug set to 1，the software can write one of the valid queue head addresses to the ASYNCLISTADDR register to allow the host controller to get the valid queue head. in order to solve that problem, this patch set the flag for Huawei Kunpeng920 There are detailed instructions and solutions in this patch: commit 2f7ac6c19997 ("USB: ehci: add workaround for Synopsys HC bug") Signed-off-by: Longfang Liu Acked-by: Alan Stern --- Changes in v3: - updated comment message Changes in v2: - Added comment message drivers/usb/host/ehci-pci.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index 1a48ab1..7ff2cbd 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -216,6 +216,13 @@ static int ehci_pci_setup(struct usb_hcd *hcd) ehci_info(ehci, "applying MosChip frame-index workaround\n"); ehci->frame_index_bug = 1; break; + case PCI_VENDOR_ID_HUAWEI: + /* Synopsys HC bug */ + if (pdev->device == 0xa239) { + ehci_info(ehci, "applying Synopsys HC workaround\n"); + ehci->has_synopsys_hc_bug = 1; + } + break; } /* optional debug port, normally in the first BAR */