From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755110AbbLDCqW (ORCPT ); Thu, 3 Dec 2015 21:46:22 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:49998 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754924AbbLDCqI (ORCPT ); Thu, 3 Dec 2015 21:46:08 -0500 X-Listener-Flag: 11101 From: Chunfeng Yun To: Mathias Nyman CC: Matthias Brugger , Felipe Balbi , Chunfeng Yun , , , , , Daniel Kurtz , Sergei Shtylyov , Greg Kroah-Hartman Subject: [PATCH] usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling Date: Fri, 4 Dec 2015 10:40:07 +0800 Message-ID: <1449196807-31785-1-git-send-email-chunfeng.yun@mediatek.com> X-Mailer: git-send-email 1.8.1.1.dirty MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org when ip fail to enter sleep mode, register access protection will be disabed, at the same time if all clocks are disabled, access register will hang up AHB bus. the common case causes ip sleep fail is that after all ports enter U3 but before ip enters sleep mode, a port receives a resume signal('K'). this will happens when such as clicks mouse to try to do remote wakeup to stop system enter suspend. so stop polling roothubs to avoid access xHCI register on bus suspend, and restart it when bus resume. Signed-off-by: Chunfeng Yun --- drivers/usb/host/xhci-mtk.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c index c9ab6a4..38635fb 100644 --- a/drivers/usb/host/xhci-mtk.c +++ b/drivers/usb/host/xhci-mtk.c @@ -696,9 +696,24 @@ static int xhci_mtk_remove(struct platform_device *dev) } #ifdef CONFIG_PM_SLEEP +/* + * if ip sleep fail, and all clocks are disabled, access register will hang + * AHB bus, so stop poll roothubs to avoid regs access on bus suspend. + * and no need to check whether ip sleep fail or not; this will cause SPM to + * wakeup system immediately after system suspend complete if ip sleep + * fail, it is what we wanted. + */ static int xhci_mtk_suspend(struct device *dev) { struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev); + struct usb_hcd *hcd = mtk->hcd; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + + xhci_dbg(xhci, "%s: stop port polling\n", __func__); + clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); + del_timer_sync(&hcd->rh_timer); + clear_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags); + del_timer_sync(&xhci->shared_hcd->rh_timer); xhci_mtk_host_disable(mtk); xhci_mtk_phy_power_off(mtk); @@ -710,11 +725,19 @@ static int xhci_mtk_suspend(struct device *dev) static int xhci_mtk_resume(struct device *dev) { struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev); + struct usb_hcd *hcd = mtk->hcd; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); usb_wakeup_disable(mtk); xhci_mtk_clks_enable(mtk); xhci_mtk_phy_power_on(mtk); xhci_mtk_host_enable(mtk); + + xhci_dbg(xhci, "%s: restart port polling\n", __func__); + set_bit(HCD_FLAG_POLL_RH, &hcd->flags); + usb_hcd_poll_rh_status(hcd); + set_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags); + usb_hcd_poll_rh_status(xhci->shared_hcd); return 0; } -- 1.8.1.1.dirty