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
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