From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH 5/6] USB: Support wakeup IRQ for suspended controllers Date: Thu, 11 Jul 2013 10:30:35 +0300 Message-ID: <51DE5F1B.8080201@ti.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Alan Stern Cc: gregkh@linuxfoundation.org, balbi@ti.com, sergei.shtylyov@cogentembedded.com, khilman@linaro.org, tony@atomide.com, ruslan.bilovol@ti.com, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org On 07/10/2013 10:08 PM, Alan Stern wrote: > 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. > OK, will do. cheers, -roger