From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hanjun Guo Subject: Re: [PATCH v2 0/2] net: thunder: Add ACPI support. Date: Thu, 13 Aug 2015 16:34:13 +0800 Message-ID: <55CC5685.4000807@linaro.org> References: <1439254717-2875-1-git-send-email-ddaney.cavm@gmail.com> <20150811.114908.1384923604512568161.davem@davemloft.net> <55CA5567.9010002@caviumnetworks.com> <20150812152337.GB5393@e104818-lin.cambridge.arm.com> <55CB67E4.8030001@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: mark.rutland@arm.com, linux-mips@linux-mips.org, david.daney@cavium.com, netdev@vger.kernel.org, rafael@kernel.org, linux-kernel@vger.kernel.org, tomasz.nowicki@linaro.org, rrichter@cavium.com, linux-acpi@vger.kernel.org, ddaney.cavm@gmail.com, sgoutham@cavium.com, David Miller , linux-arm-kernel@lists.infradead.org To: David Daney , Catalin Marinas Return-path: In-Reply-To: <55CB67E4.8030001@caviumnetworks.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 08/12/2015 11:36 PM, David Daney wrote: > On 08/12/2015 08:23 AM, Catalin Marinas wrote: >> On Tue, Aug 11, 2015 at 01:04:55PM -0700, David Daney wrote: >>> On 08/11/2015 11:49 AM, David Miller wrote: >>>> From: David Daney >>>> Date: Mon, 10 Aug 2015 17:58:35 -0700 >>>> >>>>> Change from v1: Drop PHY binding part, use fwnode_property* APIs. >>>>> >>>>> The first patch (1/2) rearranges the existing code a little with no >>>>> functional change to get ready for the second. The second (2/2) does >>>>> the actual work of adding support to extract the needed information >>>> >from the ACPI tables. >>>> >>>> Series applied. >>> >>> Thank you very much. >>> >>>> In the future it might be better structured to try and get the OF >>>> node, and if that fails then try and use the ACPI method to obtain >>>> these values. >>> >>> Our current approach, as you can see in the patch, is the opposite. >>> If ACPI >>> is being used, prefer that over the OF device tree. >>> >>> You seem to be recommending precedence for OF. It should be consistent >>> across all drivers/sub-systems, so do you really think that OF before >>> ACPI >>> is the way to go? >> >> On arm64 (unless you use a vendor kernel), DT takes precedence over ACPI >> if both arm provided to the kernel (and it's a fair assumption given >> that ACPI on ARM is still in the early days). You could also force ACPI >> with acpi=force on the kernel cmd line and the arch code will not >> unflatten the DT even if it is provided, therefore is_of_node(fwnode) >> returning false. Yes. on the other hand, if no DT is provided, will try ACPI even if no acpi=force on the kernel cmd line. >> >> I haven't looked at your driver in detail but something like AMD's >> xgbe_probe() uses a single function for both DT and ACPI with >> device_property_read_*() functions getting the information from the >> correct place in either case. The ACPI vs DT precedence is handled by >> the arch boot code, we never mix the two and confuse the drivers. >> > > My long term plan is to create something like > firmware_get_mac_address(), that would encapsulate of_get_mac_address() > and the ACPI equivalent. > > Same for firmware_phy_find_device(). I'm very keen on seeing that happens :) Thanks Hanjun