Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754609Ab3GJTIq (ORCPT ); Wed, 10 Jul 2013 15:08:46 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:41028 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754374Ab3GJTIo (ORCPT ); Wed, 10 Jul 2013 15:08:44 -0400 Date: Wed, 10 Jul 2013 15:08:43 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Roger Quadros cc: gregkh@linuxfoundation.org, , , , , , , , , Subject: Re: [PATCH 5/6] USB: Support wakeup IRQ for suspended controllers In-Reply-To: <1373473393-27552-1-git-send-email-rogerq@ti.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 Content-Length: 1217 Lines: 33 On Wed, 10 Jul 2013, Roger Quadros wrote: > 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. Oh yes, one more thing... > @@ -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 */ Please add a highly visible comment here, warning that has_wakeup_irq should never be set on systems with shared IRQs. Having both would ... well, it would indicate a really bad system design. 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/