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 <tunguyen@xxxxxxx> Signed-off-by: Thang Q. Nguyen <tqnguyen@xxxxxxx> --- 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 | 3 +++ drivers/usb/host/xhci.h | 1 + 4 files changed, 8 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 30f47d9..49d05c7 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -4061,6 +4061,9 @@ 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; diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 73a28a9..03d50e8 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1819,6 +1819,7 @@ struct xhci_hcd { /* For controller with a broken Port Disable implementation */ #define XHCI_BROKEN_PORT_PED (1 << 25) #define XHCI_LIMIT_ENDPOINT_INTERVAL_7 (1 << 26) +#define XHCI_HW_LPM_DISABLE (1 << 27) unsigned int num_active_eps; unsigned int limit_active_eps; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html