From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751244AbcBUSBE (ORCPT ); Sun, 21 Feb 2016 13:01:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39395 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750934AbcBUSA1 (ORCPT ); Sun, 21 Feb 2016 13:00:27 -0500 Date: Sun, 21 Feb 2016 15:14:00 +0200 From: "Michael S. Tsirkin" To: "Gabriel L. Somlo" Cc: gregkh@linuxfoundation.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, arnd@arndb.de, lersek@redhat.com, ralf@linux-mips.org, rmk+kernel@arm.linux.org.uk, eric@anholt.net, hanjun.guo@linaro.org, zajec5@gmail.com, sudeep.holla@arm.com, agross@codeaurora.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, qemu-devel@nongnu.org, imammedo@redhat.com, peter.maydell@linaro.org, leif.lindholm@linaro.org, ard.biesheuvel@linaro.org, pbonzini@redhat.com, kraxel@redhat.com, ehabkost@redhat.com, luto@amacapital.net, stefanha@gmail.com, revol@free.fr, matt@codeblueprint.co.uk, rth@twiddle.net Subject: Re: [PATCH v8 1/4] firmware: introduce sysfs driver for QEMU's fw_cfg device Message-ID: <20160221151050-mutt-send-email-mst@redhat.com> References: <1453990994-17801-1-git-send-email-somlo@cmu.edu> <1453990994-17801-2-git-send-email-somlo@cmu.edu> <20160221100557-mutt-send-email-mst@redhat.com> <20160221130614.GA4511@GLSMBP.INI.CMU.EDU> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160221130614.GA4511@GLSMBP.INI.CMU.EDU> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 21, 2016 at 08:06:17AM -0500, Gabriel L. Somlo wrote: > > So for all arches which support ACPI, I think this driver > > should just rely on ACPI. > > There was a discussion about that a few versions ago, and IIRC the > conclusion was not to expect the firmware to contend for fw_cfg access > after the guest kernel boots: > > https://lkml.org/lkml/2015/10/5/283 Interesting. Igor wanted to do this again recently ... I'll think it over and get back to you/list on this. > (I even had a prototype version doing what you suggested, but per the above > reference decided to drop it -- which IMHO is for the better, since otherwise > I'd have had to ifdef between ACPI and non-ACPI versions of the driver -- > see https://lkml.org/lkml/2015/11/4/534 ) I'm not sure I get it - won't you only ifdef the accessor function? -- MST