From patchwork Tue Jul 3 18:40:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Stern X-Patchwork-Id: 10504983 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 786EE60325 for ; Tue, 3 Jul 2018 18:40:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E6BA28EAA for ; Tue, 3 Jul 2018 18:40:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5CDF728EAC; Tue, 3 Jul 2018 18:40:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DBDEA28D6C for ; Tue, 3 Jul 2018 18:40:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934471AbeGCSkp (ORCPT ); Tue, 3 Jul 2018 14:40:45 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:38260 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S934381AbeGCSko (ORCPT ); Tue, 3 Jul 2018 14:40:44 -0400 Received: (qmail 6373 invoked by uid 2102); 3 Jul 2018 14:40:43 -0400 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 3 Jul 2018 14:40:43 -0400 Date: Tue, 3 Jul 2018 14:40:43 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Paul Menzel cc: USB list Subject: [RFT] Remove USB bus reset delay from OHCI handover code In-Reply-To: Message-ID: MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP I no longer have suitable hardware for testing this patch. If anyone with an OHCI host controller could try it out, I would like to hear if it causes any problems. Thank you all. Alan Stern --- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: usb-4.x/drivers/usb/host/pci-quirks.c =================================================================== --- usb-4.x.orig/drivers/usb/host/pci-quirks.c +++ usb-4.x/drivers/usb/host/pci-quirks.c @@ -783,15 +783,9 @@ static void quirk_usb_handoff_ohci(struc /* disable interrupts */ writel((u32) ~0, base + OHCI_INTRDISABLE); - /* Reset the USB bus, if the controller isn't already in RESET */ - if (control & OHCI_HCFS) { - /* Go into RESET, preserving RWC (and possibly IR) */ - writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL); - readl(base + OHCI_CONTROL); - - /* drive bus reset for at least 50 ms (7.1.7.5) */ - msleep(50); - } + /* Go into the USB_RESET state, preserving RWC (and possibly IR) */ + writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL); + readl(base + OHCI_CONTROL); /* software reset of the controller, preserving HcFmInterval */ if (!no_fminterval)