On Fri, Jun 23, 2017 at 10:02 AM, Thang Q. Nguyen <tqnguyen@xxxxxxx> wrote: > 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 > Hi, Is there any other comment on the patch? Regards, Thang Q. Nguyen -- 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