Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031784AbbKECw1 (ORCPT ); Wed, 4 Nov 2015 21:52:27 -0500 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:59609 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031599AbbKECwZ convert rfc822-to-8bit (ORCPT ); Wed, 4 Nov 2015 21:52:25 -0500 From: John Youn To: Douglas Anderson , John Youn , "balbi@ti.com" CC: Yunzhi Li , =?iso-8859-1?Q?Heiko_St=FCbner?= , "linux-rockchip@lists.infradead.org" , Julius Werner , "gregory.herrero@intel.com" , "yousaf.kaukab@intel.com" , "dinguyen@opensource.altera.com" , "gregkh@linuxfoundation.org" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 1/2] usb: dwc2: host: Fix missing device insertions Thread-Topic: [PATCH v2 1/2] usb: dwc2: host: Fix missing device insertions Thread-Index: AQHRFnahoQ51YCDXzU2eK2Io+adh6w== Date: Thu, 5 Nov 2015 02:52:21 +0000 Message-ID: <2B3535C5ECE8B5419E3ECBE30077290901DC3BA312@US01WEMBX2.internal.synopsys.com> References: <1446582629-30091-1-git-send-email-dianders@chromium.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.10.161.104] Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6741 Lines: 183 On 11/3/2015 12:31 PM, Douglas Anderson wrote: > If you've got your interrupt signals bouncing a bit as you insert your > USB device, you might end up in a state when the device is connected but > the driver doesn't know it. > > Specifically, the observed order is: > 1. hardware sees connect > 2. hardware sees disconnect > 3. hardware sees connect > 4. dwc2_port_intr() - clears connect interrupt > 5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect() > > Now you'll be stuck with the cable plugged in and no further interrupts > coming in but the driver will think we're disconnected. > > We'll fix this by checking for the missing connect interrupt and > re-connecting after the disconnect is posted. We don't skip the > disconnect because if there is a transitory disconnect we really want to > de-enumerate and re-enumerate. > > Signed-off-by: Douglas Anderson > --- > Changes in v2: > - Don't reconnect when called from _dwc2_hcd_stop() (John Youn) > > drivers/usb/dwc2/core.h | 6 ++++-- > drivers/usb/dwc2/core_intr.c | 4 ++-- > drivers/usb/dwc2/hcd.c | 40 ++++++++++++++++++++++++++++++++++++++-- > drivers/usb/dwc2/hcd_intr.c | 6 +----- > 4 files changed, 45 insertions(+), 11 deletions(-) > > diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h > index a66d3cb62b65..daa1c342cdac 100644 > --- a/drivers/usb/dwc2/core.h > +++ b/drivers/usb/dwc2/core.h > @@ -1154,12 +1154,14 @@ static inline int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg, > > #if IS_ENABLED(CONFIG_USB_DWC2_HOST) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE) > extern int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg); > -extern void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg); > +extern void dwc2_hcd_connect(struct dwc2_hsotg *hsotg); > +extern void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg, bool force); > extern void dwc2_hcd_start(struct dwc2_hsotg *hsotg); > #else > static inline int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg) > { return 0; } > -static inline void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg) {} > +static inline void dwc2_hcd_connect(struct dwc2_hsotg *hsotg) {} > +static inline void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg, bool force) {} > static inline void dwc2_hcd_start(struct dwc2_hsotg *hsotg) {} > static inline void dwc2_hcd_remove(struct dwc2_hsotg *hsotg) {} > static inline int dwc2_hcd_init(struct dwc2_hsotg *hsotg, int irq) > diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c > index 27daa42788b1..61601d16e233 100644 > --- a/drivers/usb/dwc2/core_intr.c > +++ b/drivers/usb/dwc2/core_intr.c > @@ -239,7 +239,7 @@ static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg) > dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n", > hsotg->op_state); > spin_unlock(&hsotg->lock); > - dwc2_hcd_disconnect(hsotg); > + dwc2_hcd_disconnect(hsotg, false); > spin_lock(&hsotg->lock); > hsotg->op_state = OTG_STATE_A_PERIPHERAL; > } else { > @@ -401,7 +401,7 @@ static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg) > dwc2_op_state_str(hsotg)); > > if (hsotg->op_state == OTG_STATE_A_HOST) > - dwc2_hcd_disconnect(hsotg); > + dwc2_hcd_disconnect(hsotg, false); > > dwc2_writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS); > } > diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c > index e79baf73c234..e208eac7ff57 100644 > --- a/drivers/usb/dwc2/hcd.c > +++ b/drivers/usb/dwc2/hcd.c > @@ -268,15 +268,33 @@ static void dwc2_hcd_cleanup_channels(struct dwc2_hsotg *hsotg) > } > > /** > + * dwc2_hcd_connect() - Handles connect of the HCD > + * > + * @hsotg: Pointer to struct dwc2_hsotg > + * > + * Must be called with interrupt disabled and spinlock held > + */ > +void dwc2_hcd_connect(struct dwc2_hsotg *hsotg) > +{ > + if (hsotg->lx_state != DWC2_L0) > + usb_hcd_resume_root_hub(hsotg->priv); > + > + hsotg->flags.b.port_connect_status_change = 1; > + hsotg->flags.b.port_connect_status = 1; > +} > + > +/** > * dwc2_hcd_disconnect() - Handles disconnect of the HCD > * > * @hsotg: Pointer to struct dwc2_hsotg > + * @force: If true, we won't try to reconnect even if we see device connected. > * > * Must be called with interrupt disabled and spinlock held > */ > -void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg) > +void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg, bool force) > { > u32 intr; > + u32 hprt0; > > /* Set status flags for the hub driver */ > hsotg->flags.b.port_connect_status_change = 1; > @@ -315,6 +333,24 @@ void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg) > dwc2_hcd_cleanup_channels(hsotg); > > dwc2_host_disconnect(hsotg); > + > + /* > + * Add an extra check here to see if we're actually connected but > + * we don't have a detection interrupt pending. This can happen if: > + * 1. hardware sees connect > + * 2. hardware sees disconnect > + * 3. hardware sees connect > + * 4. dwc2_port_intr() - clears connect interrupt > + * 5. dwc2_handle_common_intr() - calls here > + * > + * Without the extra check here we will end calling disconnect > + * and won't get any future interrupts to handle the connect. > + */ > + if (!force) { > + hprt0 = dwc2_readl(hsotg->regs + HPRT0); > + if (!(hprt0 & HPRT0_CONNDET) && (hprt0 & HPRT0_CONNSTS)) > + dwc2_hcd_connect(hsotg); > + } > } > > /** > @@ -2365,7 +2401,7 @@ static void _dwc2_hcd_stop(struct usb_hcd *hcd) > > spin_lock_irqsave(&hsotg->lock, flags); > /* Ensure hcd is disconnected */ > - dwc2_hcd_disconnect(hsotg); > + dwc2_hcd_disconnect(hsotg, true); > dwc2_hcd_stop(hsotg); > hsotg->lx_state = DWC2_L3; > hcd->state = HC_STATE_HALT; > diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c > index bda0b21b850f..03504ac2fecc 100644 > --- a/drivers/usb/dwc2/hcd_intr.c > +++ b/drivers/usb/dwc2/hcd_intr.c > @@ -350,11 +350,7 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg) > dev_vdbg(hsotg->dev, > "--Port Interrupt HPRT0=0x%08x Port Connect Detected--\n", > hprt0); > - if (hsotg->lx_state != DWC2_L0) > - usb_hcd_resume_root_hub(hsotg->priv); > - > - hsotg->flags.b.port_connect_status_change = 1; > - hsotg->flags.b.port_connect_status = 1; > + dwc2_hcd_connect(hsotg); > hprt0_modify |= HPRT0_CONNDET; > > /* > Acked-by: John Youn Tested-by: John Youn Tested on Synopsys HAPS platform IP v3.20a. Regards, John -- 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/