Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755804AbaKRQHh (ORCPT ); Tue, 18 Nov 2014 11:07:37 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:34826 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755773AbaKRQHf (ORCPT ); Tue, 18 Nov 2014 11:07:35 -0500 Date: Tue, 18 Nov 2014 11:07:34 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Kever Yang cc: Paul Zimmerman , Felipe Balbi , Dinh Nguyen , , Heiko Stuebner , , , , , , , , Roy Li , Greg Kroah-Hartman , , Subject: Re: [PATCH v2] usb: dwc2: resume root hub when device detect with suspend state In-Reply-To: <1416273684-11300-1-git-send-email-kever.yang@rock-chips.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Nov 2014, Kever Yang wrote: > After we implement the bus_suspend/resume, auto suspend id enabled. > The root hub will be auto suspend if there is no device connected, > we need to resume the root hub when a device connect detect. > > This patch tested on rk3288. > > Signed-off-by: Roy Li > Signed-off-by: Kever Yang > --- > > Changes in v2: > - add definition for hcd structure > - remove check for bus->root_hub > > drivers/usb/dwc2/hcd_intr.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c > index 551ba87..680206f 100644 > --- a/drivers/usb/dwc2/hcd_intr.c > +++ b/drivers/usb/dwc2/hcd_intr.c > @@ -329,6 +329,7 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg) > { > u32 hprt0; > u32 hprt0_modify; > + struct usb_hcd *hcd = (struct usb_hcd *)hsotg->priv; > > dev_vdbg(hsotg->dev, "--Port Interrupt--\n"); > > @@ -354,6 +355,10 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg) > hsotg->flags.b.port_connect_status = 1; > hprt0_modify |= HPRT0_CONNDET; > > + /* resume root hub? */ > + if (hcd->state == HC_STATE_SUSPENDED) > + usb_hcd_resume_root_hub(hcd); You should be aware that it's not safe to use hcd->state for anything in a host controller driver. That field is owned by usbcore, not by the HCD, and it is not protected by any locks. Thus, for example, hcd->state does not get set to HC_STATE_SUSPENDED until some time after the bus_suspend routine has returned. A port-change interrupt might occur during that time interval. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/