From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [PATCH] acpi: bus: handle power manageable but no _PSC/_PRx case Date: Mon, 10 Sep 2012 08:38:07 +0800 Message-ID: <20120910003805.GA1590@mint-spring.sh.intel.com> References: <1346053126-7646-1-git-send-email-aaron.lu@intel.com> <201209071346.01900.rjw@sisk.pl> <504A0579.3000109@intel.com> <201209072032.55469.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga01.intel.com ([192.55.52.88]:65109 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755744Ab2IJAiK (ORCPT ); Sun, 9 Sep 2012 20:38:10 -0400 Content-Disposition: inline In-Reply-To: <201209072032.55469.rjw@sisk.pl> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: Len Brown , linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, Aaron Lu On Fri, Sep 07, 2012 at 08:32:55PM +0200, Rafael J. Wysocki wrote: > On Friday, September 07, 2012, Aaron Lu wrote: > > On 09/07/2012 07:46 PM, Rafael J. Wysocki wrote: > > >> Yes, on a test system, when I try to put a device into D3 cold and ACPI > > >> will complain that I can't due to its parent is in a even lower power > > >> state UNKNOWN(255), this parent device is power manageable but has no > > >> _PSC and _PRx defined. > > > > > > Perhaps we can force _PS0 for such devices to start with, so that we know > > > for sure that the initial state is D0? > > > > Sounds good, I'll update the patch, thanks for the advice. > > Actually, I suppose we can do something like the appended patch instead. > > I wonder if it works around the particular problem you're seeing? Yes, thanks. Reviewed-by: Aaron Lu -Aaron > > Rafael > > > --- > drivers/acpi/bus.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > Index: linux/drivers/acpi/bus.c > =================================================================== > --- linux.orig/drivers/acpi/bus.c > +++ linux/drivers/acpi/bus.c > @@ -229,7 +229,16 @@ static int __acpi_bus_get_power(struct a > result = psc; > } > /* The test below covers ACPI_STATE_UNKNOWN too. */ > - if (result <= ACPI_STATE_D2) { > + if (result == ACPI_STATE_D0) { > + /* > + * If we were unsure about the device parent's power state up to > + * this point, the fact that the device is in D0 implies that > + * the parent has to be in D0 too. > + */ > + if (device->parent > + && device->parent->power.state == ACPI_STATE_UNKNOWN) > + device->parent->power.state = ACPI_STATE_D0; > + } else if (result <= ACPI_STATE_D2) { > ; /* Do nothing. */ > } else if (device->power.flags.power_resources) { > int error = acpi_power_get_inferred_state(device, &result);