From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: exynos5422-odroid-xu3: MCPM: only 6 of 8 CPUs coming online Date: Thu, 23 Oct 2014 08:56:23 -0700 Message-ID: <7hfveeaifs.fsf@deeprootsystems.com> References: <7133556.456161412823997169.JavaMail.weblogic@epml02> <7hzjd4lxc5.fsf@deeprootsystems.com> <54485433.2040008@samsung.com> <54485730.10803@samsung.com> <54485B99.2000703@samsung.com> <54485E99.9020004@samsung.com> <54485FDA.8070508@samsung.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-pd0-f177.google.com ([209.85.192.177]:61789 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754750AbaJWP41 (ORCPT ); Thu, 23 Oct 2014 11:56:27 -0400 Received: by mail-pd0-f177.google.com with SMTP id v10so1244291pde.36 for ; Thu, 23 Oct 2014 08:56:27 -0700 (PDT) In-Reply-To: (Abhilash Kesavan's message of "Thu, 23 Oct 2014 16:59:10 +0530") Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Abhilash Kesavan Cc: Abhijeet Dev , Joonyoung Shim , Mauro Ribeiro , linux-samsung-soc@vger.kernel.org, k.chander@samsung.com, Mauro Ribeiro , kgene.kim@samsung.com, Me2 Abhilash Kesavan writes: > The change was based on my reading of the platsmp file of the > Odroid-xu3 3.10 kernel and issues experienced previously. From what I > understand, the platsmp code in 3.10 kernel is trying to reset the A7s > and my change just bypasses the check (no magic here ). The change was > only suggested as a workaround to get 8 cores up using MCPM and not an > actual fix. I had explained this in my mail to Kevin. So, if this > were to be mainlined we would probably need to use something like > exynos_core_restart in mcpm along with the workaround. But, this is > all guesswork on my part and someone with knowledge of the 3.10 > kernel/bootloader needs to comment. Unfortunately, the harkernel tree git repo doesn't help understand where the change came from because an entire v3.10.y based Samsung BSP is checked into the tree on top of a v3.8.y kernel in a single commit !!! Abhilash, in the absence of the original author, could write up a patch with your change? Or, if you can help me with a detailed changelog, I can work on the patch. I don't have any exynos docs, so it would be good to have a description of what reading/writing to that register are actually doing. Also, can you explain what you meant by using exynos_core_restart? I don't see that function in mainline. Kevin