From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hanjun Guo Subject: Re: [Linaro-acpi] [RFC part1 PATCH 1/7] ACPI: Make ACPI core running without PCI on ARM64 Date: Tue, 10 Dec 2013 10:53:20 +0800 Message-ID: <52A68220.30306@linaro.org> References: <1386088611-2801-1-git-send-email-hanjun.guo@linaro.org> <20131209115050.GA19163@arm.com> <52A5C024.5050702@linaro.org> <201312091735.05014.arnd@arndb.de> <20131209165548.GE19163@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131209165548.GE19163@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Catalin Marinas , Arnd Bergmann Cc: Tomasz Nowicki , Mark Rutland , Matthew Garrett , "linaro-kernel@lists.linaro.org" , Russell King - ARM Linux , "patches@linaro.org" , Olof Johansson , Linus Walleij , Daniel Lezcano , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Will Deacon , "linaro-acpi@lists.linaro.org" , "linux-acpi@vger.kernel.org" , "rob.herring@calxeda.com" , Bjorn Helgaas , "linux-arm-kernel@lists.infradead.org" List-Id: linux-acpi@vger.kernel.org On 2013-12-10 0:55, Catalin Marinas wrote: > On Mon, Dec 09, 2013 at 04:35:04PM +0000, Arnd Bergmann wrote: >> On Monday 09 December 2013, Hanjun Guo wrote: >>> On 2013-12-9 19:50, Catalin Marinas wrote: >>>> On Mon, Dec 09, 2013 at 04:12:24AM +0000, Hanjun Guo wrote: >>>>> >>>>> I think the concern here is that ACPI is only for server platform or not. >>>>> >>>>> Since ACPI has lots of content related to power management, I think ACPI >>>>> can be used for mobile devices and other platform too, not only for ARM >>>>> servers, and with this patch, we can support both requirement. >>>> >>>> 'Can be used' is one thing, will it really be used is another? I don't >>>> think so, it was (well, is) difficult enough to make the transition to >>>> FDT, I don't see how ACPI would solve the current issues. >> >> Exactly. In particular we don't want people to get the wrong idea about >> where we are heading, so making it possible to use this code on embedded >> systems for me is a reason *not* to take the patch. > > I agree. > >>>> I see ACPI as a server distro requirement and there are indeed benefits >>>> in abstracting the hardware behind standard description, AML. Of course, >>>> this would work even better with probe-able buses like PCIe and I'm >>>> pretty sure this would be the case on high-end servers. But even if a >>>> server distro like RHEL supports a SoC without PCIe, I would expect them >>>> to only provide a single binary Image with CONFIG_PCI enabled. >>>> >>>> This patch is small enough and allows ACPI build with !CONFIG_PCI for >>>> the time being but longer term I would expect such SoCs without PCI to >>>> be able to run on a kernel with CONFIG_PCI enabled. >>> >>> Yes, we will support PCI in ACPI in the long run, and we just make PCI >>> optional for ACPI in this patch. >> >> Do you mean there is a problem running your code with PCI /enabled/ at the >> moment? If so, I'd suggest fixing that instead since you will have to fix >> it anyway. > > CONFIG_PCI does not exist on arm64 yet (we have some internal patches > but may not be ready to be posted before the holidays; they try to share > code with other archs, so more discussions before merging). We could add > CONFIG_PCI and some dummy functions on arm64 for development (not to be > upstreamed) or Hanjun could continue to use the current patch before we > get PCI working. Thanks for the suggestion, I will continue to use the current patch, and I will rework or rebase this one when PCI is working. Hanjun