Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932204AbbBQFl7 (ORCPT ); Tue, 17 Feb 2015 00:41:59 -0500 Received: from mail-pd0-f170.google.com ([209.85.192.170]:35078 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbbBQFl4 (ORCPT ); Tue, 17 Feb 2015 00:41:56 -0500 From: Sneeker Yeh X-Google-Original-From: Sneeker Yeh To: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Felipe Balbi , Greg Kroah-Hartman , Mathias Nyman , Grant Likely , Huang Rui , Kishon Vijay Abraham I , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org Cc: Andy Green , Jassi Brar , Sneeker Yeh Subject: [PATCH v4 1/5] xhci: add a quirk for device disconnection errata for Synopsis Designware USB3 core Date: Tue, 17 Feb 2015 13:41:33 +0800 Message-Id: <1424151697-2084-2-git-send-email-Sneeker.Yeh@tw.fujitsu.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1424151697-2084-1-git-send-email-Sneeker.Yeh@tw.fujitsu.com> References: <1424151697-2084-1-git-send-email-Sneeker.Yeh@tw.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5935 Lines: 144 This issue is defined by a three-way race at disconnect, between 1) Class driver interrupt endpoint resheduling attempts if the ISR gave an ep error event due to device detach (it would try 3 times) 2) Disconnect interrupt on PORTSC_CSC, which is cleared by hub thread asynchronously 3) The hardware IP was configured in silicon with - DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1 - Synopsys IP version is < 3.00a The IP will auto-suspend itself on device detach with some phy-specific interval after CSC is cleared by 2) If 2) and 3) complete before 1), the interrupts it expects will not be generated by the autosuspended IP, leading to a deadlock. Even later disconnection procedure would detect that corresponding urb is still in-progress and issue a ep stop command, auto-suspended IP still won't respond to that command. this defect would result in this when device detached: ------------------------------------------------------- [ 99.603544] usb 4-1: USB disconnect, device number 2 [ 104.615254] xhci-hcd xhci-hcd.0.auto: xHCI host not responding to stop endpoint command. [ 104.623362] xhci-hcd xhci-hcd.0.auto: Assuming host is dying, halting host. [ 104.653261] xhci-hcd xhci-hcd.0.auto: Host not halted after 16000 microseconds. [ 104.660584] xhci-hcd xhci-hcd.0.auto: Non-responsive xHCI host is not halting. [ 104.667817] xhci-hcd xhci-hcd.0.auto: Completing active URBs anyway. [ 104.674198] xhci-hcd xhci-hcd.0.auto: HC died; cleaning up ------------------------------------------------------ As a result, when device detached, we desired to postpone "PORTCSC clear" behind "disable slot". it's found that all executed ep command related to disconnetion, are executed before "disable slot". Signed-off-by: Sneeker Yeh --- drivers/usb/host/xhci-hub.c | 4 ++++ drivers/usb/host/xhci.c | 31 +++++++++++++++++++++++++++++++ drivers/usb/host/xhci.h | 24 ++++++++++++++++++++++++ 3 files changed, 59 insertions(+) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index a7865c4..3b8f7fc 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -368,6 +368,10 @@ static void xhci_clear_port_change_bit(struct xhci_hcd *xhci, u16 wValue, port_change_bit = "warm(BH) reset"; break; case USB_PORT_FEAT_C_CONNECTION: + if ((xhci->quirks & XHCI_DISCONNECT_QUIRK) && + !(readl(addr) & PORT_CONNECT)) + return; + status = PORT_CSC; port_change_bit = "connect"; break; diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index ec8ac16..1fb8c1c 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3580,6 +3580,35 @@ command_cleanup: return ret; } +static void xhci_try_to_clear_csc(struct usb_hcd *hcd, int dev_port_num) +{ + int max_ports; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + __le32 __iomem **port_array; + u32 status; + + /* print debug info */ + if (hcd->speed == HCD_USB3) { + max_ports = xhci->num_usb3_ports; + port_array = xhci->usb3_ports; + } else { + max_ports = xhci->num_usb2_ports; + port_array = xhci->usb2_ports; + } + + if (dev_port_num > max_ports) { + xhci_err(xhci, "%s() port number invalid", __func__); + return; + } + status = readl(port_array[dev_port_num - 1]); + + /* write 1 to clear */ + if (!(status & PORT_CONNECT) && (status & PORT_CSC)) { + status = xhci_port_state_to_neutral(status); + writel(status | PORT_CSC, port_array[dev_port_num - 1]); + } +} + /* * At this point, the struct usb_device is about to go away, the device has * disconnected, and all traffic has been stopped and the endpoints have been @@ -3645,6 +3674,8 @@ void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev) xhci_ring_cmd_db(xhci); spin_unlock_irqrestore(&xhci->lock, flags); + if (xhci->quirks & XHCI_DISCONNECT_QUIRK) + xhci_try_to_clear_csc(hcd, udev->portnum); /* * Event command completion handler will free any data structures * associated with the slot. XXX Can free sleep? diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 9745147..cb74706 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1560,6 +1560,30 @@ struct xhci_hcd { #define XHCI_SPURIOUS_WAKEUP (1 << 18) /* For controllers with a broken beyond repair streams implementation */ #define XHCI_BROKEN_STREAMS (1 << 19) +/* + * This issue is defined by a three-way race at disconnect in Synopsis USB3 IP, + * between + * 1) Class driver interrupt endpoint resheduling attempts if the ISR gave an ep + * error event due to device detach (it would try 3 times) + * 2) Disconnect interrupt on PORTSC_CSC, which is cleared by hub thread + * asynchronously + * 3) The hardware IP was configured in silicon with + * - DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1 + * - Synopsys IP version is < 3.00a + * The IP will auto-suspend itself on device detach with some phy-specific + * interval after CSC is cleared by 2) + * + * If 2) and 3) complete before 1), the interrupts it expects will not be + * generated by the autosuspended IP, leading to a deadlock. Even later + * disconnection procedure would detect that corresponding urb is still + * in-progress and issue a ep stop command, auto-suspended IP still won't + * respond to that command. + * + * As a result, when device detached, it's needed to postpone "PORTCSC clear" + * behind "disable slot". it's found that all executed ep command related to + * disconnetion, are executed before "disable slot". + */ +#define XHCI_DISCONNECT_QUIRK (1 << 20) unsigned int num_active_eps; unsigned int limit_active_eps; /* There are two roothubs to keep track of bus suspend info for */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/