From mboxrd@z Thu Jan 1 00:00:00 1970 From: Egger Christoph Subject: Re: [PATCH] xen/acpi-stub: Disable it b/c the acpi_processor_add is no longer called. Date: Fri, 22 Mar 2013 15:44:14 +0100 Message-ID: <514C6E3E.6050207@amazon.de> References: <1363962480-1366-1-git-send-email-konrad.wilk@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1363962480-1366-1-git-send-email-konrad.wilk@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: jinsong.liu@intel.com, xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org I think, Xen can get C and P states from ACPI itself. Why is Dom0 needed as a dependency at all? Christoph On 22.03.13 15:28, Konrad Rzeszutek Wilk wrote: > With the Xen ACPI stub code (CONFIG_XEN_STUB=y) enabled, the power > C and P states are no longer uploaded to the hypervisor. > > The reason is that the Xen CPU hotplug code: xen-acpi-cpuhotplug.c > and the xen-acpi-stub.c register themselves as the "processor" type object. > > That means the generic processor (processor_driver.c) stops > working and it does not call (acpi_processor_add) which populates the > > per_cpu(processors, pr->id) = pr; > > structure. The 'pr' is gathered from the acpi_processor_get_info function > which does the job of finding the C-states and figuring out PBLK address. > > The 'processors->pr' is then later used by xen-acpi-processor.c (the one that > uploads C and P states to the hypervisor). Since it is NULL, we end > skip the gathering of _PSD, _PSS, _PCT, etc and never upload the power > management data. > > The end result is that enabling the CONFIG_XEN_STUB in the build means that > xen-acpi-processor is not working anymore. > > This temporary patch fixes it by marking the XEN_STUB driver as > BROKEN until this can be properly fixed. > > CC: jinsong.liu@intel.com > Signed-off-by: Konrad Rzeszutek Wilk > --- > drivers/xen/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig > index 5a32232..67af155 100644 > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -182,7 +182,7 @@ config XEN_PRIVCMD > > config XEN_STUB > bool "Xen stub drivers" > - depends on XEN && X86_64 > + depends on XEN && X86_64 && BROKEN > default n > help > Allow kernel to install stub drivers, to reserve space for Xen drivers, >