From patchwork Fri Jan 3 08:40:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 11316625 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 0B3EB930 for ; Fri, 3 Jan 2020 08:40:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE7602464E for ; Fri, 3 Jan 2020 08:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726313AbgACIkT (ORCPT ); Fri, 3 Jan 2020 03:40:19 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:58172 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726181AbgACIkT (ORCPT ); Fri, 3 Jan 2020 03:40:19 -0500 Received: from 61-220-137-37.hinet-ip.hinet.net ([61.220.137.37] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1inIVC-0003Sp-4G; Fri, 03 Jan 2020 08:40:14 +0000 From: Kai-Heng Feng To: mathias.nyman@intel.com, gregkh@linuxfoundation.org, stern@rowland.harvard.edu Cc: acelan.kao@canonical.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kai-Heng Feng Subject: [PATCH 1/3] xhci: Ensure link state is U3 after setting USB_SS_PORT_LS_U3 Date: Fri, 3 Jan 2020 16:40:06 +0800 Message-Id: <20200103084008.3579-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.17.1 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The xHCI spec doesn't specify the upper bound of U3 transition time. For some devices 20ms is not enough, so we need to make sure the link state is in U3 before further actions. I've tried to use U3 Entry Capability by setting U3 Entry Enable in config register, however the port change event for U3 transition interrupts the system suspend process. For now let's use the less ideal method by polling PLS. Signed-off-by: Kai-Heng Feng --- drivers/usb/host/xhci-hub.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 7a3a29e5e9d2..2b2e9d004dbf 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1228,6 +1228,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, break; case USB_PORT_FEAT_LINK_STATE: temp = readl(ports[wIndex]->addr); + xhci_dbg(xhci, "before setting link state, actual port %d-%d status = 0x%0x\n", hcd->self.busnum, wIndex + 1, temp); /* Disable port */ if (link_state == USB_SS_PORT_LS_SS_DISABLED) { xhci_dbg(xhci, "Disable port %d\n", wIndex); @@ -1316,9 +1317,17 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, msleep(20); /* wait device to enter */ spin_lock_irqsave(&xhci->lock, flags); - temp = readl(ports[wIndex]->addr); - if (link_state == USB_SS_PORT_LS_U3) + if (link_state == USB_SS_PORT_LS_U3) { + retval = xhci_handshake(ports[wIndex]->addr, PORT_PLS_MASK, XDEV_U3, 80 * 1000); + if (retval) + xhci_dbg(xhci, "polling XDEV_U3 on port %d-%d timeout\n", hcd->self.busnum, wIndex + 1); + bus_state->suspended_ports |= 1 << wIndex; + } + + temp = readl(ports[wIndex]->addr); + xhci_dbg(xhci, "after setting link state, port %d-%d status = 0x%0x\n", hcd->self.busnum, wIndex + 1, temp); + break; case USB_PORT_FEAT_POWER: /*