On Sun, Jul 09, 2017 at 12:38:19PM +0700, Thang Q. Nguyen wrote:
> 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?
Relax, it's the middle of the merge window, we can't do anything with
patches until after 4.13-rc1 comes out a the earliest...
greg k-h
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