From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?B?Um9ow6Fy?= Subject: Re: [PATCH v3] dell-rbtn: Ignore ACPI notifications if device is suspended Date: Mon, 18 Apr 2016 14:35:47 +0200 Message-ID: <20160418123547.GK29406@pali> References: <1457740175-8327-1-git-send-email-gabriele.mzt@gmail.com> <20160328173309.GA26086@dvhart-mobl5.amr.corp.intel.com> <4072492.lANJWhSkYa@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wm0-f49.google.com ([74.125.82.49]:38115 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075AbcDRMfv (ORCPT ); Mon, 18 Apr 2016 08:35:51 -0400 Content-Disposition: inline In-Reply-To: <4072492.lANJWhSkYa@vostro.rjw.lan> Sender: platform-driver-x86-owner@vger.kernel.org List-ID: To: Darren Hart , Gabriele Mazzotta Cc: "D. Jared Dominguez" , "platform-driver-x86@vger.kernel.org" , Alex Hung , Andrei Borzenkov , "linux-kernel@vger.kernel.org" , "Rafael J. Wysocki" On Tuesday 29 March 2016 15:11:35 Rafael J. Wysocki wrote: > On Monday, March 28, 2016 10:33:09 AM Darren Hart wrote: > > On Thu, Mar 24, 2016 at 12:24:56PM +0100, Gabriele Mazzotta wrote: > > > 2016-03-24 10:39 GMT+01:00 Pali Roh=C3=A1r = : > > > > On Monday 21 March 2016 16:13:34 Gabriele Mazzotta wrote: > > > >> 2016-03-21 13:17 GMT+01:00 Pali Roh=C3=A1r : > > > >> > On Friday 18 March 2016 23:44:23 Gabriele Mazzotta wrote: > > > >> >> +#ifdef CONFIG_PM_SLEEP > > > >> >> +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *c= ontext) > > > >> >> +{ > > > >> >> + struct rbtn_data *rbtn_data =3D context; > > > >> >> + > > > >> >> + rbtn_data->suspended =3D false; > > > >> >> +} > > > >> >> + > > > >> >> +static int rbtn_suspend(struct device *dev) > > > >> >> +{ > > > >> >> + struct acpi_device *device =3D to_acpi_device(dev); > > > >> >> + struct rbtn_data *rbtn_data =3D acpi_driver_data(devi= ce); > > > >> >> + > > > >> >> + rbtn_data->suspended =3D true; > > > >> >> + > > > >> >> + return 0; > > > >> >> +} > > > >> >> + > > > >> >> +static int rbtn_resume(struct device *dev) > > > >> >> +{ > > > >> >> + struct acpi_device *device =3D to_acpi_device(dev); > > > >> >> + struct rbtn_data *rbtn_data =3D acpi_driver_data(devi= ce); > > > >> >> + acpi_status status; > > > >> >> + > > > >> >> + /* > > > >> >> + * Clear the flag only after we received the extra > > > >> >> + * ACPI notification. > > > >> >> + */ > > > >> >> + status =3D acpi_os_execute(OSL_NOTIFY_HANDLER, > > > >> >> + rbtn_acpi_clear_flag, rbtn_data); > > > >> >> + if (ACPI_FAILURE(status)) > > > >> >> + rbtn_data->suspended =3D false; > > > >> > > > > >> > I case when acpi_os_execute success it calls rbtn_acpi_clear= _flag, > > > >> > right? And that will set suspended to false. When acpi_os_ex= ecute fails, > > > >> > then it set suspended too to false... Then whole acpi_os_exe= cute doing > > > >> > just "barrier" after which suspended flag can be set to fals= e. So I > > > >> > think rbtn_acpi_clear_flag function is not needed here. > > > >> > > > > >> > Cannot you pass NULL or empty function pointer as callback? = Or what was > > > >> > reason to do that flag clearing at "two places"? > > > >> > > > >> acpi_os_execute doesn't wait for the callback to be executed, = so > > > >> I can't clear the flag from rbtn_resume. > > > > > > > > acpi_os_execute calls callback asynchronously later? Or what ex= actly do it? > > >=20 > > > In this case, it adds the callback to the kacpi_notify_wq workque= ue > > > for deferred execution. > >=20 > > +Rafael for context/advice on the use of acpi_os_execute here. > >=20 > > This is true, but a quick scan through that call path doesn't tell = me why we > > would need to call it here instead of just setting rbtn_data->suspe= nded =3D false. > > The comment suggests waiting for the event, but is that what this i= s doing? It > > appears to me to be immediately scheduling the function to a work q= ueue, not > > waiting for the event notifier. >=20 > I think this is supposed to work as a barrier. That is, it will only= run after > all events in the queue have been processed. >=20 > I'm not sure if that's necessary, though. >=20 > Thanks, > Rafael >=20 Darren, Gabriele, what is state of this patch? Bug is not still fixed, right? --=20 Pali Roh=C3=A1r pali.rohar@gmail.com