From: Chris.Packham@alliedtelesis.co.nz (Chris Packham) Date: Thu, 6 Nov 2014 19:49:22 +0000 Subject: [RFC PATCH] ARM: mvebu: Let the device-tree determine smp_ops In-Reply-To: <20141106144950.GA4974@lunn.ch> References: <1415249396-2985-1-git-send-email-chris.packham@alliedtelesis.co.nz> <20141106144950.GA4974@lunn.ch> Message-ID: <545BD0C2.6000408@alliedtelesis.co.nz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 11/07/2014 03:49 AM, Andrew Lunn wrote: > On Thu, Nov 06, 2014 at 05:49:56PM +1300, Chris Packham wrote: >> The machine specific SMP operations can be configured either via >> setup_arch or via arm_dt_init_cpu_maps. For the ARMADA_370_XP_DT devices >> both of these are called and setup_arch wins because it is called last. >> This means that it is not possible to substitute a different set of SMP >> operations via the device-tree. >> >> All of the ARMADA_370_XP_DT compatible devices are either single core or >> declare an enable-method in the dts (via one of armada-xp-mv78230.dtsi, >> armada-xp-mv78260.dtsi or armada-xp-mv78460.dtsi). Remove the smp >> assignment from board-v7.c so that the SMP operations set via the >> device-tree aren't discarded. >> >> Signed-off-by: Chris Packham >> --- >> Hi, >> >> (This is the first patch I've sent to the arm-lkml so beware of my newbie-ness) > Hi Chris > > Congratulations on a good looking patch. Nice changelog, has a > signed-off-by, comments are bellow the ---. All good. > > It is however a good idea to Cc: the mvebu maintainers. I added a few > people to Cc:. Thanks for the warm welcome. I actually thought the same thing after I hit send, thanks for filling in the Cc list for me. >> I'm working on a new board that uses a integrated CPU that according to the >> vendor is "based on the ARMADA-XP", more on that to come in the future >> hopefully. > A packet processor chip with an embedded CPU? Next generation > Prestera? No need to answer that if you don't want to. You guess correctly. Not sure how much I can say without falling foul of our NDA but they know I intend on trying to get this stuff upstream rather than being locked into their particular SDK. >> For the most part things just work if I use a .dts based on the >> mv78260. > >> This is my attempt at fixing the problem by not setting mdesc.smp for the >> ARMADA_370_XP_DT machines thus preventing setup_arch from overriding what has >> been setup by arm_dt_init_cpu_maps. > You really need Thomas or Gregory to Ack this patch, but to me it > looks correct. Interestingly, this machine descriptor is used by 370, > which is a single processor. The smp operations are useless, so your > patch is also partly a cleanup. > > Andrew