From patchwork Mon Nov 26 16:57:26 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 201890 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 435FC2C0085 for ; Tue, 27 Nov 2012 04:12:24 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Td2E8-0003Nd-BO; Mon, 26 Nov 2012 17:12:12 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Td2Bb-0001gg-R8 for kernel-team@lists.ubuntu.com; Mon, 26 Nov 2012 17:09:36 +0000 Received: from 189.58.19.107.dynamic.adsl.gvt.net.br ([189.58.19.107] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Td2Bb-0006mg-5W; Mon, 26 Nov 2012 17:09:35 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 156/270] usb: Don't enable LPM if the exit latency is zero. Date: Mon, 26 Nov 2012 14:57:26 -0200 Message-Id: <1353949160-26803-157-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Cc: Sarah Sharp X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarah Sharp commit ae8963adb4ad8c5f2a89ca1d99fb7bb721e7599f upstream. Some USB 3.0 devices signal that they don't implement Link PM by having all zeroes in the U1/U2 exit latencies in their SuperSpeed BOS descriptor. Don found that a Western Digital device he has experiences transfer errors when LPM is enabled. The lsusb shows the U1/U2 exit latencies are set to zero: Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 22 bNumDeviceCaps 2 SuperSpeed USB Device Capability: bLength 10 bDescriptorType 16 bDevCapabilityType 3 bmAttributes 0x00 Latency Tolerance Messages (LTM) Supported wSpeedsSupported 0x000e Device can operate at Full Speed (12Mbps) Device can operate at High Speed (480Mbps) Device can operate at SuperSpeed (5Gbps) bFunctionalitySupport 1 Lowest fully-functional device speed is Full Speed (12Mbps) bU1DevExitLat 0 micro seconds bU2DevExitLat 0 micro seconds The fix is to not enable LPM for a particular link state if we find its corresponding exit latency is zero. This patch should be backported to kernels as old as 3.5, that contain the commit 1ea7e0e8e3d0f50901d335ea4178ab2aa8c88201 "USB: Add support to enable/disable USB3 link states." Signed-off-by: Sarah Sharp Reported-by: Don Zickus Tested-by: Don Zickus Signed-off-by: Herton Ronaldo Krzesinski --- drivers/usb/core/hub.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 70223d5..209815a 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3294,6 +3294,16 @@ static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev, enum usb3_link_state state) { int timeout; + __u8 u1_mel = udev->bos->ss_cap->bU1devExitLat; + __le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat; + + /* If the device says it doesn't have *any* exit latency to come out of + * U1 or U2, it's probably lying. Assume it doesn't implement that link + * state. + */ + if ((state == USB3_LPM_U1 && u1_mel == 0) || + (state == USB3_LPM_U2 && u2_mel == 0)) + return; /* We allow the host controller to set the U1/U2 timeout internally * first, so that it can change its schedule to account for the