Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264063AbTEOUyx (ORCPT ); Thu, 15 May 2003 16:54:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264098AbTEOUyx (ORCPT ); Thu, 15 May 2003 16:54:53 -0400 Received: from ida.rowland.org ([192.131.102.52]:6148 "HELO ida.rowland.org") by vger.kernel.org with SMTP id S264063AbTEOUyw (ORCPT ); Thu, 15 May 2003 16:54:52 -0400 Date: Thu, 15 May 2003 17:07:42 -0400 (EDT) From: Alan Stern X-X-Sender: stern@ida.rowland.org To: Paul Fulghum cc: Greg KH , Andrew Morton , "linux-kernel@vger.kernel.org" , Arnd Bergmann , , USB development list Subject: Re: Test Patch: 2.5.69 Interrupt Latency In-Reply-To: <1053007957.2025.23.camel@diemos> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1124 Lines: 33 On 15 May 2003, Paul Fulghum wrote: > I have a question about the wakeup_hc() code in general: > > when waking in response to a resume event, > the current code sets the USBCMD_FGR (force global resume) > and USBCMD_EGSM (enter global suspend mode) bits, > waits 20ms and clears both bits to start sending EOP signal. > > According to the datasheet, the controller itself > (not software) sets the FGR bit on detection of > a resume event. 20ms after the USBSTS_RD indication, > software should clear both the FGR and EGSM bits. > > My reading of this is that the line: > > outw(USBCMD_FGR | USBCMD_EGSM, io_addr + USBCMD); > > before the 20ms wait should not be necessary. > > Am I reading this correctly? I interpret it the same way as you. I tried removing that line from the driver, and it continued to work just fine. So it looks like you are right. 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/