Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932165Ab3GRIdq (ORCPT ); Thu, 18 Jul 2013 04:33:46 -0400 Received: from mail-qa0-f50.google.com ([209.85.216.50]:45978 "EHLO mail-qa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757276Ab3GRIdo (ORCPT ); Thu, 18 Jul 2013 04:33:44 -0400 MIME-Version: 1.0 In-Reply-To: <20130717132736.GA7614@arwen.pp.htv.fi> References: <20130715165209.GA6000@kroah.com> <20130716063117.GA30320@kroah.com> <20130717075706.GC5291@arwen.pp.htv.fi> <20130717132736.GA7614@arwen.pp.htv.fi> Date: Thu, 18 Jul 2013 16:33:43 +0800 Message-ID: Subject: Re: [PATCH] usb: udc: add gadget state kobject uevent From: Rong Wang To: balbi@ti.com Cc: Greg KH , Arnd Bergmann , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Rong.Wang@csr.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1750 Lines: 48 On Wed, Jul 17, 2013 at 9:27 PM, Felipe Balbi wrote: > On Wed, Jul 17, 2013 at 09:04:54PM +0800, Rong Wang wrote: >> Hi Felipe, >> >> On Wed, Jul 17, 2013 at 3:57 PM, Felipe Balbi wrote: >> > Hi, >> > >> > On Mon, Jul 15, 2013 at 11:31:17PM -0700, Greg KH wrote: >> >> > The question is since we default GADGET, so the g_mass_storage.ko is >> >> > installed early but connecting to a host PC >> >> > is randomly, But the udev has no idea when a host PC connects our device. >> >> > >> >> > So we consider it's reasonable to let the udev know the GADGET device state. >> >> > Is there any alternative to our question? >> >> >> >> I thought we already export events for gadget device states, have you >> >> looked for them? I can't dig through the code at the moment, but this >> >> seems like a pretty common issue... >> >> >> >> Felipe, any ideas? >> > >> > we already expose that in sysfs. IIRC udev can act on sysfs changes, >> > no ? >> >> I do not know if udev can polling sysfs file content change. I'll study this. >> >> But the change is triggered by calling usb_gadget_set_state, and I find >> composite framework do not call this. Then we should do this common work >> in every udc driver? > > yes. Only the UDC driver knows when the controller is moving among those > states. OK. I got that. But I think it may be more reasonable for the udc driver to maintain a work queue to handle the state change since this operation mostly happen in ISR ? > > -- > balbi -- 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/