Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755015Ab3GJQXq (ORCPT ); Wed, 10 Jul 2013 12:23:46 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:50250 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754756Ab3GJQXk (ORCPT ); Wed, 10 Jul 2013 12:23:40 -0400 From: Roger Quadros To: CC: , , , , , , , , , , Roger Quadros Subject: [PATCH 5/6] USB: Support wakeup IRQ for suspended controllers Date: Wed, 10 Jul 2013 19:23:13 +0300 Message-ID: <1373473393-27552-1-git-send-email-rogerq@ti.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1373473081-27181-1-git-send-email-rogerq@ti.com> References: <1373473081-27181-1-git-send-email-rogerq@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3438 Lines: 93 Some platforms e.g. ehci-omap can generate an interrupt (i.e. remote wakeup) even when the controller is suspended i.e. HW_ACCESSIBLE is cleared. Introduce a flag "has_wakeup_irq" in struct usb_hcd to indicate such cases. We tackle this case by disabling the IRQ, scheduling a hub resume and enabling back the IRQ after the controller has resumed. This ensures that the IRQ handler runs only after the controller is accessible. Signed-off-by: Roger Quadros --- drivers/usb/core/hcd.c | 21 ++++++++++++++++++++- include/linux/usb/hcd.h | 3 +++ 2 files changed, 23 insertions(+), 1 deletions(-) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 014dc99..933d8f1 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2161,6 +2161,11 @@ static void hcd_resume_work(struct work_struct *work) usb_lock_device(udev); usb_remote_wakeup(udev); usb_unlock_device(udev); + if (HCD_IRQ_DISABLED(hcd)) { + /* We can now process IRQs so enable IRQ */ + clear_bit(HCD_FLAG_IRQ_DISABLED, &hcd->flags); + enable_irq(hcd->irq); + } } /** @@ -2248,7 +2253,21 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd) */ local_irq_save(flags); - if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd))) + if (unlikely(HCD_DEAD(hcd))) + rc = IRQ_NONE; + else if (unlikely(!HCD_HW_ACCESSIBLE(hcd) && hcd->has_wakeup_irq)) { + /* + * We got a wakeup interrupt while the controller was + * suspending or suspended. We can't handle it now, so + * disable the IRQ and resume the root hub (and hence + * the controller too). + */ + disable_irq_nosync(hcd->irq); + set_bit(HCD_FLAG_IRQ_DISABLED, &hcd->flags); + usb_hcd_resume_root_hub(hcd); + + rc = IRQ_HANDLED; + } else if (unlikely(!HCD_HW_ACCESSIBLE(hcd))) rc = IRQ_NONE; else if (hcd->driver->irq(hcd) == IRQ_NONE) rc = IRQ_NONE; diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index 1e88377..5eb9f85 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -110,6 +110,7 @@ struct usb_hcd { #define HCD_FLAG_WAKEUP_PENDING 4 /* root hub is resuming? */ #define HCD_FLAG_RH_RUNNING 5 /* root hub is running? */ #define HCD_FLAG_DEAD 6 /* controller has died? */ +#define HCD_FLAG_IRQ_DISABLED 7 /* Interrupt was disabled */ /* The flags can be tested using these macros; they are likely to * be slightly faster than test_bit(). @@ -120,6 +121,7 @@ struct usb_hcd { #define HCD_WAKEUP_PENDING(hcd) ((hcd)->flags & (1U << HCD_FLAG_WAKEUP_PENDING)) #define HCD_RH_RUNNING(hcd) ((hcd)->flags & (1U << HCD_FLAG_RH_RUNNING)) #define HCD_DEAD(hcd) ((hcd)->flags & (1U << HCD_FLAG_DEAD)) +#define HCD_IRQ_DISABLED(hcd) ((hcd)->flags & (1U << HCD_FLAG_IRQ_DISABLED)) /* Flags that get set only during HCD registration or removal. */ unsigned rh_registered:1;/* is root hub registered? */ @@ -132,6 +134,7 @@ struct usb_hcd { unsigned wireless:1; /* Wireless USB HCD */ unsigned authorized_default:1; unsigned has_tt:1; /* Integrated TT in root hub */ + unsigned has_wakeup_irq:1; /* Can IRQ when suspended */ unsigned int irq; /* irq allocated */ void __iomem *regs; /* device memory/io */ -- 1.7.4.1 -- 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/