Re: [v2 1/1] usb:host:xhci support option to disable xHCI 1.0 USB2 HW LPM

From: Rob Herring
Date: Tue May 30 2017 - 18:32:38 EST


On Sat, May 20, 2017 at 02:24:56PM +0700, Thang Q. Nguyen wrote:
> XHCI specification 1.1 does not require xHCI 1.0 compliant controllers
> to always enable hardware USB2 LPM.
> However, the current xHCI driver always enable it by setting HLE=1 when
> seeing HLC=1. This makes certain xHCI controllers that have broken USB2
> HW LPM fail to work as there is no way to disable this feature.
> This patch adds support to control disabling USB2 Hardware LPM via
> DT/ACPI attribute.
>
> Signed-off-by: Tung Nguyen <tunguyen@xxxxxxx>
> Signed-off-by: Thang Q. Nguyen <tqnguyen@xxxxxxx>
> ---
> 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 +

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> drivers/usb/host/xhci-plat.c | 3 +++
> drivers/usb/host/xhci.c | 7 ++++++-
> drivers/usb/host/xhci.h | 1 +
> 4 files changed, 11 insertions(+), 1 deletions(-)