From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [RFC][PATCH v3 3/3] input: i8042: Avoid resetting controller on system suspend/resume Date: Tue, 6 Oct 2015 15:43:08 -0700 Message-ID: <20151006224308.GD31850@dtor-ws> References: <10641052.oOBhM6BU9G@vostro.rjw.lan> <3385784.1Q539YNd1G@vostro.rjw.lan> <20151006223442.GA31850@dtor-ws> <1927174.T9TA7zgbS1@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:35054 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752847AbbJFWnL (ORCPT ); Tue, 6 Oct 2015 18:43:11 -0400 Content-Disposition: inline In-Reply-To: <1927174.T9TA7zgbS1@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Linux PM list , Linux Kernel Mailing List , ACPI Devel Maling List , Alan Stern , Daniel Vetter , Bjorn Helgaas , Linux PCI On Wed, Oct 07, 2015 at 01:08:30AM +0200, Rafael J. Wysocki wrote: > On Tuesday, October 06, 2015 03:34:42 PM Dmitry Torokhov wrote: > > On Wed, Oct 07, 2015 at 12:53:49AM +0200, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki > > > > > > If the upcoming system suspend is not going to be handled by the > > > platform firmware, like in the suspend-to-idle case, it is not > > > necessary to reset the controller in i8042_pm_suspend(), so avoid > > > doing that. > > > > > > Moreover, if the system resume currently in progress has not been > > > started by the platform firmware, like in the suspend-to-idle case, > > > i8042_controller_resume() need not be called by i8042_pm_resume(), > > > so avoid doing that too in that case. > > > > > > Additionally, try to catch the event that woke up the system by > > > calling the interrupt handler early during system resume if it has > > > not been started by the platform firmware. > > > > > > Signed-off-by: Rafael J. Wysocki > > > --- > > > drivers/input/serio/i8042.c | 15 +++++++++++++-- > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > Index: linux-pm/drivers/input/serio/i8042.c > > > =================================================================== > > > --- linux-pm.orig/drivers/input/serio/i8042.c > > > +++ linux-pm/drivers/input/serio/i8042.c > > > @@ -24,6 +24,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > > > > #include > > > > > > @@ -1170,7 +1171,8 @@ static int i8042_pm_suspend(struct devic > > > { > > > int i; > > > > > > - i8042_controller_reset(true); > > > + if (pm_suspend_via_firmware()) > > > + i8042_controller_reset(true); > > > > > > /* Set up serio interrupts for system wakeup. */ > > > for (i = 0; i < I8042_NUM_PORTS; i++) { > > > @@ -1183,6 +1185,14 @@ static int i8042_pm_suspend(struct devic > > > return 0; > > > } > > > > > > +static int i8042_pm_resume_noirq(struct device *dev) > > > +{ > > > + if (!pm_resume_via_firmware()) > > > + i8042_interrupt(0, NULL); > > > + > > > + return 0; > > > +} > > > + > > > static int i8042_pm_resume(struct device *dev) > > > { > > > int i; > > > @@ -1199,7 +1209,7 @@ static int i8042_pm_resume(struct device > > > * to bring it in a sane state. (In case of S2D we expect > > > * BIOS to reset the controller for us.) > > > */ > > > - return i8042_controller_resume(true); > > > + return pm_resume_via_firmware() ? i8042_controller_resume(true) : 0; > > > > What happens if we were going to suspend via firmware so we reset the > > controller but then we got wakeup condition and we actually did not > > suspend. What pm_resume_via_firmware() will return in this case? > > It will return 'false'. Do we need to resume the controller then? Yes. > But I guess > 'false' should be passed to i8042_controller_resume() in that case? Yes, we do not need to reset the controller in this case, just reactivate multiplexing mode, etc. Thanks. -- Dmitry