Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757202AbdGLIHL (ORCPT ); Wed, 12 Jul 2017 04:07:11 -0400 Received: from mail-pg0-f43.google.com ([74.125.83.43]:36213 "EHLO mail-pg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757007AbdGLIHD (ORCPT ); Wed, 12 Jul 2017 04:07:03 -0400 From: "Thang Q. Nguyen" To: Greg Kroah-Hartman , Rob Herring , Mark Rutland , Mathias Nyman , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Thang Nguyen , Phong Vo , Loc Ho , Tung Nguyen , patches@apm.com Subject: [PATCH v4 1/1] usb:host:xhci support option to disable the xHCI USB2 HW LPM Date: Wed, 12 Jul 2017 15:06:48 +0700 Message-Id: <1499846808-25981-1-git-send-email-tqnguyen@apm.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3464 Lines: 91 XHCI specification 1.1 does not require xHCI-compliant controllers to always enable hardware USB2 LPM. However, the current xHCI driver always enable it when seeing HLC=1. This patch supports an option for users to control disabling USB2 Hardware LPM via DT/ACPI attribute. This option is needed in case user would like to disable this feature. For example, their xHCI controller has its USB2 HW LPM broken. Signed-off-by: Tung Nguyen Signed-off-by: Thang Q. Nguyen --- Changes since v3: - Bypass updating LPM parameters when HW LPM is optionally disabled. Changes since v2: - Change code to disable HW LPM as an option for user which is set via ACPI/DT. Changes since v1: - Update DT/ACPI attribute and corresponding codes from HLE to LPM to be consistent with other attribute names. --- Documentation/devicetree/bindings/usb/usb-xhci.txt | 1 + drivers/usb/host/xhci-plat.c | 3 +++ drivers/usb/host/xhci.c | 6 ++++++ drivers/usb/host/xhci.h | 1 + 4 files changed, 11 insertions(+), 0 deletions(-) diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt index 2d80b60..ae6e484 100644 --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt @@ -26,6 +26,7 @@ Required properties: Optional properties: - clocks: reference to a clock + - usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM - usb3-lpm-capable: determines if platform is USB3 LPM capable - quirk-broken-port-ped: set if the controller has broken port disable mechanism diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index c04144b..9028fb5 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -267,6 +267,9 @@ static int xhci_plat_probe(struct platform_device *pdev) goto disable_clk; } + if (device_property_read_bool(sysdev, "usb2-lpm-disable")) + xhci->quirks |= XHCI_HW_LPM_DISABLE; + if (device_property_read_bool(sysdev, "usb3-lpm-capable")) xhci->quirks |= XHCI_LPM_SUPPORT; diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 56f85df..73b24bc 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -4060,6 +4060,9 @@ static int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd, !udev->lpm_capable) return -EPERM; + if (xhci->quirks & XHCI_HW_LPM_DISABLE) + return -EPERM; + if (!udev->parent || udev->parent->parent || udev->descriptor.bDeviceClass == USB_CLASS_HUB) return -EPERM; @@ -4177,6 +4180,9 @@ static int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev) !udev->lpm_capable) return 0; + if (xhci->quirks & XHCI_HW_LPM_DISABLE) + return 0; + /* we only support lpm for non-hub device connected to root hub yet */ if (!udev->parent || udev->parent->parent || udev->descriptor.bDeviceClass == USB_CLASS_HUB) diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 3c6da1f..3cbf4a9 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1820,6 +1820,7 @@ struct xhci_hcd { #define XHCI_BROKEN_PORT_PED (1 << 25) #define XHCI_LIMIT_ENDPOINT_INTERVAL_7 (1 << 26) #define XHCI_U2_DISABLE_WAKE (1 << 27) +#define XHCI_HW_LPM_DISABLE (1 << 28) unsigned int num_active_eps; unsigned int limit_active_eps; -- 1.7.1