From mboxrd@z Thu Jan 1 00:00:00 1970 From: chunfeng yun Subject: Re: [RESEND PATCH v2] usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling Date: Tue, 12 Jan 2016 09:48:24 +0800 Message-ID: <1452563304.28863.1.camel@mhfsdcap03> References: <1452216517-3765-1-git-send-email-chunfeng.yun@mediatek.com> <5693B5C8.6090201@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5693B5C8.6090201@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Mathias Nyman Cc: Mathias Nyman , Matthias Brugger , Felipe Balbi , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org, linux-mediatek@lists.infradead.org, Daniel Kurtz , Sergei Shtylyov , Greg Kroah-Hartman List-Id: linux-mediatek@lists.infradead.org Hi, 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 > > --- > > 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 > Thank you! > -Mathias >