Re: [PATCH v3 1/1] usb:host:xhci support option to disable the xHCI USB2 HW LPM

From: Rob Herring
Date: Mon Jun 26 2017 - 15:03:18 EST


On Fri, Jun 23, 2017 at 10:02:12AM +0700, Thang Q. Nguyen 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(-)

Acked-by: Rob Herring <robh@xxxxxxxxxx>