Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751313AbaKFWLf (ORCPT ); Thu, 6 Nov 2014 17:11:35 -0500 Received: from mail-oi0-f45.google.com ([209.85.218.45]:54878 "EHLO mail-oi0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750998AbaKFWLd (ORCPT ); Thu, 6 Nov 2014 17:11:33 -0500 MIME-Version: 1.0 In-Reply-To: <1415237402-24665-1-git-send-email-kever.yang@rock-chips.com> References: <1415237402-24665-1-git-send-email-kever.yang@rock-chips.com> Date: Thu, 6 Nov 2014 14:11:32 -0800 X-Google-Sender-Auth: EjDgPgMQY9CzRG3k7Qgr_O8nT6I Message-ID: Subject: Re: [PATCH v2] usb: dwc2: add bus suspend/resume for dwc2 From: Julius Werner To: Kever Yang Cc: Paul Zimmerman , Felipe Balbi , Dinh Nguyen , romain.perier@gmail.com, Heiko Stuebner , Douglas Anderson , Sonny Rao , addy ke , Eddie Cai , Jianqun Xu , han jiang , =?UTF-8?B?5oi05YWL6ZyW?= , Tao Huang , linux-rockchip@lists.infradead.org, Greg Kroah-Hartman , "linux-usb@vger.kernel.org" , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 5, 2014 at 5:30 PM, Kever Yang wrote: > Hcd controller needs bus_suspend/resume, dwc2 controller make > root hub generate suspend/resume signal with hprt0 register > when work in host mode. > After the root hub enter suspend, we can make controller enter > low power state with PCGCTL register. You say you do this, but I don't actually see you doing it (for the not-connected case)? > > We also update the lx_state for hsotg state. > > This patch has tested on rk3288 with suspend/resume. > > Signed-off-by: Kever Yang > --- > > Changes in v2: > - update commit message > - make dwc2 suspend/resume sourcecode work > > drivers/usb/dwc2/hcd.c | 78 +++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 67 insertions(+), 11 deletions(-) > > diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c > index 0a0e6f0..01a415b 100644 > --- a/drivers/usb/dwc2/hcd.c > +++ b/drivers/usb/dwc2/hcd.c > @@ -1471,6 +1471,30 @@ static void dwc2_port_suspend(struct dwc2_hsotg *hsotg, u16 windex) > } > } > > +static void dwc2_port_resume(struct dwc2_hsotg *hsotg) > +{ > + u32 hprt0; > + > + /* After clear the Stop PHY clock bit, we should wait for a moment > + * for PLL work stable with clock output. > + */ > + writel(0, hsotg->regs + PCGCTL); > + usleep_range(2000, 4000); > + > + hprt0 = dwc2_read_hprt0(hsotg); > + hprt0 |= HPRT0_RES; > + writel(hprt0, hsotg->regs + HPRT0); > + hprt0 &= ~HPRT0_SUSP; > + /* according to USB2.0 Spec 7.1.7.7, the host must send the resume > + * signal for at least 20ms > + */ > + usleep_range(20000, 25000); > + > + hprt0 &= ~HPRT0_RES; > + writel(hprt0, hsotg->regs + HPRT0); > + hsotg->lx_state = DWC2_L0; > +} > + > /* Handles hub class-specific requests */ > static int dwc2_hcd_hub_control(struct dwc2_hsotg *hsotg, u16 typereq, > u16 wvalue, u16 windex, char *buf, u16 wlength) > @@ -1516,17 +1540,7 @@ static int dwc2_hcd_hub_control(struct dwc2_hsotg *hsotg, u16 typereq, > case USB_PORT_FEAT_SUSPEND: > dev_dbg(hsotg->dev, > "ClearPortFeature USB_PORT_FEAT_SUSPEND\n"); > - writel(0, hsotg->regs + PCGCTL); > - usleep_range(20000, 40000); > - > - hprt0 = dwc2_read_hprt0(hsotg); > - hprt0 |= HPRT0_RES; > - writel(hprt0, hsotg->regs + HPRT0); > - hprt0 &= ~HPRT0_SUSP; > - usleep_range(100000, 150000); > - > - hprt0 &= ~HPRT0_RES; > - writel(hprt0, hsotg->regs + HPRT0); I'm curious why this didn't change lx_state back to DWC2_L0 before... Paul, do you know? > + dwc2_port_resume(hsotg); > break; > > case USB_PORT_FEAT_POWER: > @@ -2299,6 +2313,44 @@ static void _dwc2_hcd_stop(struct usb_hcd *hcd) > usleep_range(1000, 3000); > } > > +static int _dwc2_hcd_suspend(struct usb_hcd *hcd) > +{ > + struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd); > + u32 hprt0; > + > + if (!((hsotg->op_state == OTG_STATE_B_HOST) || > + (hsotg->op_state == OTG_STATE_A_HOST))) > + return 0; > + > + if (hsotg->lx_state != DWC2_L0) What if the port is in L1 state? I don't think the driver supports LPM right now, but the DWC2_L1 enum is defined so it may one day in the future. Let's maybe at least add a TODO. > + return 0; In your original ChromiumOS version of this patch, you also set PCGCTL_STOPPCLK here if the port was not connected. Is there a reason that changed (does it not actually save power or something)? > + > + hprt0 = dwc2_read_hprt0(hsotg); > + if (hprt0 & HPRT0_CONNSTS) > + dwc2_port_suspend(hsotg, 1); The contract for bus_suspend() is that it will suspend all ports not yet suspended, keep track of those ports and then only resume those in bus_resume() (compare, for example, how XHCI keeps track of that with xhci_bus_state.bus_suspended in xhci_bus_suspend/resume()). So you need something here to remember whether this function suspended the port or whether it had already been suspended, and then only resume the port in bus_resume() in the former case. Note that dwc2_port_suspend() changes lx_state to DWC_L2 (at least in the version I'm looking at right now), so you can't just rely on that unless you explicitly set it back to something else here. > + > + return 0; > +} > + > +static int _dwc2_hcd_resume(struct usb_hcd *hcd) > +{ > + struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd); > + u32 hprt0; > + > + if (!((hsotg->op_state == OTG_STATE_B_HOST) || > + (hsotg->op_state == OTG_STATE_A_HOST))) > + return 0; > + > + if (hsotg->lx_state != DWC2_L2) > + return 0; > + > + hprt0 = dwc2_read_hprt0(hsotg); > + if ((hprt0 & HPRT0_CONNSTS) && (hprt0 & HPRT0_SUSP)) > + dwc2_port_resume(hsotg); > + > + return 0; > +} > + > /* Returns the current frame number */ > static int _dwc2_hcd_get_frame_number(struct usb_hcd *hcd) > { > @@ -2669,6 +2721,10 @@ static struct hc_driver dwc2_hc_driver = { > .hub_status_data = _dwc2_hcd_hub_status_data, > .hub_control = _dwc2_hcd_hub_control, > .clear_tt_buffer_complete = _dwc2_hcd_clear_tt_buffer_complete, > +#ifdef CONFIG_PM > + .bus_suspend = _dwc2_hcd_suspend, > + .bus_resume = _dwc2_hcd_resume, > +#endif > }; > > /* > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/