Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758199Ab2J3PTH (ORCPT ); Tue, 30 Oct 2012 11:19:07 -0400 Received: from mga14.intel.com ([143.182.124.37]:24328 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751906Ab2J3PTE convert rfc822-to-8bit (ORCPT ); Tue, 30 Oct 2012 11:19:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,679,1344236400"; d="scan'208";a="211277022" From: "Liu, Jinsong" To: Konrad Rzeszutek Wilk CC: Konrad Rzeszutek Wilk , "linux-kernel@vger.kernel.org" , Jan Beulich , "xen-devel@lists.xen.org" Subject: RE: [Xen-devel] [PATCH 1/2] Xen acpi pad implement Thread-Topic: [Xen-devel] [PATCH 1/2] Xen acpi pad implement Thread-Index: AQHNtqOwTi91BiFLfUibRvXA4zlK85fR5CRg Date: Tue, 30 Oct 2012 15:18:59 +0000 Message-ID: References: <5089676602000078000A4928@nat28.tlf.novell.com> <508A89CB020000780008E6ED@nat28.tlf.novell.com> <20121026201409.GF2708@phenom.dumpdata.com> <20121029123950.GK2708@phenom.dumpdata.com> <20121030133720.GA27463@phenom.dumpdata.com> In-Reply-To: <20121030133720.GA27463@phenom.dumpdata.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1769 Lines: 43 Konrad Rzeszutek Wilk wrote: >>> +config XEN_ACPI_PAD_STUB >>> + bool >>> + depends on XEN_DOM0 && X86_64 && ACPI >>> + default n >>> + >> >> This Kconfig is pointless, if CONFIG_XEN_ACPI_PAD_STUB = n, native >> pad would successfully registerred, and then mwait #UD (we would >> revert df88b2d96e36d9a9e325bfcd12eb45671cbbc937, right?). So xen >> stub logic should unconditionally built-in kernel. > > > Potentially. Keep in mind that there is no need to built this if the > kernel is not built with ACPI. Sure, 'obj-$(CONFIG_XEN_DOM0) +=' is enough. (XEN_DOM0 depends on ACPI). >>> +subsys_initcall(xen_acpi_pad_stub_init); >> >> I'm still confused. In this way there are xen-acpi-pad-stub.c and >> xen-acpi-pad.c, and you want to let xen-acpi-pad loaded as module, >> right? how can xen-acpi-pad logic work when it was insmoded? > > Via the register/unregister calls that this provides? Or does ACPI bus > drivers get immediately called once the call acpi_bus_register_driver? But when xen stub driver registerred, real xen pad ops has not been hooked to stub ops. > > Or can one 'poke' the 'add' and 'remove' calls so that once the "true" > PAD driver is loaded it will restart the ops->add call? I think we'd better not to use xen pad stub approach. Technically it's complicated, say, how to match xen_acpi_pad driver w/ pad device? when and how to invoke .add method? how to avoid native pad loading risk? etc. I didn't find its obivous advantages, so how about keep simpler approach? Thanks, Jinsong -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/