From patchwork Sat Jan 9 14:47:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugene Korenevsky X-Patchwork-Id: 360058 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, USER_AGENT_SANE_1 autolearn=ham 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 37583C433DB for ; Sat, 9 Jan 2021 14:48:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F052023998 for ; Sat, 9 Jan 2021 14:48:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725893AbhAIOsb (ORCPT ); Sat, 9 Jan 2021 09:48:31 -0500 Received: from mail.astralinux.ru ([217.74.38.120]:50485 "EHLO mail.astralinux.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbhAIOsa (ORCPT ); Sat, 9 Jan 2021 09:48:30 -0500 Received: from [95.24.186.126] (account ekorenevsky@astralinux.ru HELO himera.home) by astralinux.ru (CommuniGate Pro SMTP 6.3.4) with ESMTPSA id 2776747; Sat, 09 Jan 2021 17:46:21 +0300 Date: Sat, 9 Jan 2021 17:47:36 +0300 From: Eugene Korenevsky To: linux-usb@vger.kernel.org Cc: Alan Stern , Greg Kroah-Hartman Subject: [PATCH v2] ehci: fix EHCI host controller initialization sequence Message-ID: <20210109144736.GA4829@himera.home> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org According to EHCI spec, EHCI HC clears USBSTS.HCHalted whenever USBCMD.RS=1. However, it is a good practice to wait some time after setting USBCMD.RS (approximately 100ms) until USBSTS.HCHalted become zero. Instead, previous version of ehci_run() wrote 1 to USBCMD.RS, issued read to USBCMD and waited for 5 ms. That worked incorrectly at least for VirtualBox's EHCI virtual HC and caused accidental hangs. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211095 Signed-off-by: Eugene Korenevsky --- drivers/usb/host/ehci-hcd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index e358ae17d51e..490473af4906 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -574,6 +574,7 @@ static int ehci_run (struct usb_hcd *hcd) struct ehci_hcd *ehci = hcd_to_ehci (hcd); u32 temp; u32 hcc_params; + int rc; hcd->uses_new_polling = 1; @@ -629,9 +630,18 @@ static int ehci_run (struct usb_hcd *hcd) down_write(&ehci_cf_port_reset_rwsem); ehci->rh_state = EHCI_RH_RUNNING; ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag); - ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */ - msleep(5); + + /* Wait until HCD become operational */ + rc = ehci_handshake(ehci, &ehci->regs->status, STS_HALT, 0, 100 * 1000); + up_write(&ehci_cf_port_reset_rwsem); + + if (rc) { + ehci_err(ehci, "USB %x.%x, handshake error: %d\n", + ((ehci->sbrn & 0xf0)>>4), (ehci->sbrn & 0x0f), rc); + return rc; + } + ehci->last_periodic_enable = ktime_get_real(); temp = HC_VERSION(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));