From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH v7 1/9] arm64: dts: exynos: Add dts files for 64-bit Exynos5433 SoC Date: Fri, 03 Apr 2015 08:39:13 +0900 Message-ID: <551DD321.6030707@samsung.com> References: <1426637856-3730-1-git-send-email-cw00.choi@samsung.com> <1426637856-3730-2-git-send-email-cw00.choi@samsung.com> <20150330160940.GA13731@leverpostej> <5519E2B6.2030905@samsung.com> <20150402173558.GB30669@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <20150402173558.GB30669@leverpostej> Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland Cc: "kgene@kernel.org" , Marc Zyngier , "arnd@arndb.de" , "olof@lixom.net" , Catalin Marinas , Will Deacon , "inki.dae@samsung.com" , "chanho61.park@samsung.com" , "sw0312.kim@samsung.com" , "jh80.chung@samsung.com" , "ideal.song@samsung.com" , "a.kesavan@samsung.com" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 04/03/2015 02:35 AM, Mark Rutland wrote: > On Tue, Mar 31, 2015 at 12:56:38AM +0100, Chanwoo Choi wrote: >> Hi Mark, >> >> On 03/31/2015 01:09 AM, Mark Rutland wrote: >>> Hi, >>> >>> On Wed, Mar 18, 2015 at 12:17:28AM +0000, Chanwoo Choi wrote: >>>> This patch adds new Exynos5433 dtsi to support 64-bit Exynos5433 SoC based on >>>> Octal core CPUs (quad Cortex-A57 and quad Cortex-A53). And Exynos5433 supports >>>> PSCI (Power State Coordination Interface) v0.1. >>>> >>>> This patch includes following dt node to support Exynos5433 SoC: >>>> 1. Octa core for big.LITTLE architecture >>>> - Cortex-A53 LITTLE Quad-core >>>> - Cortex-A57 big Quad-core >>>> - Support PSCI v0.1 >>> >>> Is CPU0 hotplug still broken, or has the FW been fixed? >> >> CPU0 hotplug is still not working. >> >>> >>> I'm very worried about adding a DT that's known broken, especially when >>> we have no idea as to if/when the FW will be fixed judging from prior >>> replies. >> >> As I replied, I can not fix the FW because I don't have any code of FW. > > Surely you are able to contact those who do? > >> I don't have any solution to fix it on Linux kernel level. >> >> So, If you agree, I can add the comment of CPU0 hotplug issue on DT file. > > I disagree. I do not want to add a DT that is known to be broken; > especially when we have no idea how to fix it. It creates long-term > maintenance pain for everyone, and marginal gain for few. A comment does > nothing to aid the end-user. > > So NAK to the PSCI node and PSCI enable method in this dts until we > either have a working firmware, or a reasonable mechanism to handle the > deficiency. There is only CPU0 hotplug issue. Excpet CPU{1-7} are well working. To fix this issue, we must need the help of firmware developer. But, We never get the any help. Also, as I mentioned on previous mail, all Exynos SoCs can not turn off the CPU0. I've never seen Exynos SoC that CP0 hotplug is possible. Thanks, Chanwoo Choi