Re: [RESEND PATCH v2] usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling
From: chunfeng yun
Date: Mon Jan 11 2016 - 20:48:40 EST
On Mon, 2016-01-11 at 16:01 +0200, Mathias Nyman wrote:
> On 08.01.2016 03:28, Chunfeng Yun wrote:
> > when ip fails to enter sleep mode, register access protection will
> > be disabled, at the same time if all clocks are disabled, access
> > register will hang up AHB bus.
> > the common case causes ip sleep failure is that after all ports
> > enter U3 but before ip enters sleep mode, a port receives a resume
> > signal('K'). this will happens when such as clicks mouse to try to
> > do remote-wakeup to stop system enter suspend.
> > so stop polling root hubs to avoid access xHCI register on bus
> > suspend, and restart it when bus resumes.
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > ---
> > drivers/usb/host/xhci-mtk.c | 23 +++++++++++++++++++++++
> The xhci Mediatek (xhci-mtk etc) support is in usb-next and should be available first time
> in 4.5-rc1 kernel.
> I'll forward fixes for it once 4.5-rc1 is out, they should end up in final 4.5