Ben Guthro
2013-Jul-27 15:33 UTC
Re: [PATCH v4 0/5] Xen/ACPI: support sleep state entering on hardware reduced systems
On Jul 27, 2013, at 9:51 AM, "Rafael J. Wysocki" <rjw@sisk.pl> wrote:> On Thursday, June 27, 2013 11:01:58 AM Ben Guthro wrote: >> In version 3.4 acpi_os_prepare_sleep() got introduced in parallel with >> reduced hardware sleep support, and the two changes didn''t get >> synchronized: The new code doesn''t call the hook function (if so >> requested). Fix this, requiring a boolean parameter to be added to the >> hook function to distinguish "extended" from "legacy" sleep. >> >> This requires adjusting TXT, but the adjustments only go as far as >> failing the extended mode call (since, looking at the TXT interface, >> there doesn''t even appear to be precautions to deal with that >> alternative interface). >> >> The hypervisor change underlying this is commit 62d1a69 ("ACPI: support >> v5 (reduced HW) sleep interface") on the master branch of >> git://xenbits.xen.org/xen.git. >> >> Signed-off-by: Ben Guthro <benjamin.guthro@citrix.com> >> Signed-off-by: Jan Beulich <jbeulich@suse.com> >> Cc: Richard L Maliszewski <richard.l.maliszewski@intel.com> >> Cc: Gang Wei <gang.wei@intel.com> >> Cc: Shane Wang <shane.wang@intel.com> >> Cc: Bob Moore <robert.moore@intel.com> >> Cc: Rafaell J. Wysocki <rjw@sisk.pl> >> Cc: linux-acpi@vger.kernel.org >> Cc: tboot-devel@lists.sourceforge.net >> >> v2: Extend description to include reference to hypervisor side change >> v3: Split into multiple patches, separating subsystems >> Remove bool parameters, in favor of u8 >> v4: Remove linux/acpi.h dependencies >> Further patch split to break out acpica from OSL >> More bool vs u8 fixes >> >> Ben Guthro (5): >> acpi: Remove need to include linux/acpi.h in common acpica code >> acpi: Call acpi_os_prepare_sleep hook in reduced hardware sleep path >> acpi: Adjust linux acpi OS functions to new extended parameter >> x86/tboot: Fail extended mode reduced hardware sleep >> xen/acpi: notify xen when reduced hardware sleep is available > > The ongoing discussion means to me that the ACPICA maintainers don''t want > acpi_os_prepare_sleep() and quite frankly I understand them, because ACPICA > is about implementing the spec and not about things beyond it. > > This means that patch [1/5] goes away. > > That said, at the same time we need to address the problem at hand, which > is to make Xen work with the reduced HW sleep. > > For that, I don''t honestly think that modifying acpi_os_prepare_sleep() the > way the patchset is doing it is appropriate and the change of the meaning of > the arguments is simply disgusting. > > To me, it would be much cleaner to add acpi_os_prepare_extended_sleep() > specifically to be called by acpi_hw_extended_sleep() and make tboot and Xen > use that. > > This way or another, we''ll need to live with one more divergence between the > upstream ACPICA and the Linux ACPICA code because of that, but that''d be just > a few added lines in acpi_hw_extended_sleep(), so I suppose it wouldn''t be > such a big deal. >Ok, thank you for the review, and being open to addressing the problem at hand, without a full architecture rework (not to say that that discussion is not also needed) I will try to make some time next week to rework the patch set to address these concerns, and submit a new series. Thanks Ben> Thanks, > Rafael > > > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center.