Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752657AbbH2KHs (ORCPT ); Sat, 29 Aug 2015 06:07:48 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:34623 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752370AbbH2KHq (ORCPT ); Sat, 29 Aug 2015 06:07:46 -0400 MIME-Version: 1.0 X-Originating-IP: [95.23.101.120] In-Reply-To: References: <1440749769-10135-1-git-send-email-javier@osg.samsung.com> <55E174F3.1030202@samsung.com> <55E17C56.4080200@osg.samsung.com> Date: Sat, 29 Aug 2015 12:07:45 +0200 Message-ID: Subject: Re: [PATCH] ARM: exynos_defconfig: Enable big.LITTLE CPUidle support From: Javier Martinez Canillas To: Krzysztof Kozlowski Cc: Javier Martinez Canillas , Linux Kernel , Kukjin Kim , Thierry Reding , Anand Moon , Russell King , "linux-samsung-soc@vger.kernel.org" , Sjoerd Simons , Lukasz Majewski , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3737 Lines: 95 Hello Krzysztof, On Sat, Aug 29, 2015 at 11:55 AM, Krzysztof Kozlowski wrote: > 2015-08-29 18:33 GMT+09:00 Javier Martinez Canillas : >> Hello Krzysztof, >> >> On 08/29/2015 11:01 AM, Krzysztof Kozlowski wrote: >>> W dniu 28.08.2015 o 17:16, Javier Martinez Canillas pisze: >>>> Some Exynos big.LITTLE boards (i.e: Exynos5420 and Exynos5800 based >>>> Chromebooks) have proper firmware that allow the big.LITTLE CPUidle >>>> driver to work correctly, so enable support for this. >>>> >>>> Signed-off-by: Javier Martinez Canillas >>>> >>>> --- >>>> Kukjin and Krzysztof, >>>> >>>> As you know there are other boards like the Exynos5422 based Odroid XU{3,4} >>>> whose firmware is broken due leaving CCI in secure mode which means that the >>>> kernel MCPM support can't properly manage CCI. >>>> >>>> So if you pick this patch, it should be tested in kernelci before appearing >>>> in linux-next to prevent any boot issues. >>>> >>>> But if that happens, I believe that is better to do a fix / workaround in >>>> those broken platforms since nothing prevents users to enable this option >>>> anyways. For example the CCI device node could be disabled in the DTS. >>>> >>>> arch/arm/configs/exynos_defconfig | 1 + >>>> 1 file changed, 1 insertion(+) >>> >>> On Odroid XU3L (next-20150828, Hardkernel u-boot) boot hangs just after: >>> >> >> Thanks for testing, I was expecting that is just that I don't have a >> Odroid XU{3,4} board for test here, I guess I should get one. >> >>> [ 2.568650] dwmmc_exynos 12200000.mmc: num-slots property not found, >>> assuming 1 slot is available >>> >>> ... so no. NACK :). First the boards, firmware, bootloader or kernel >> >> Agreed with the nack :) >> >>> code have to be fixed. >>> >> >> Or disable CCI, could you please test the following patch [0] so I >> can post it properly? > > It fixes the boot hang but causes other issues. Not all CPUs boot (I Thanks for testing. > tested it on Chanho Park's patch for fixing CPU boot with SWRESET): > [ 0.010781] CPU0: update cpu_capacity 448 > [ 0.010839] CPU0: thread -1, cpu 0, socket 1, mpidr 80000100 > [ 0.011098] Setting up static identity map for 0x40008280 - 0x400082d8 > [ 0.056329] CPU1: update cpu_capacity 448 > [ 0.056337] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001 > [ 0.071100] CPU2: update cpu_capacity 448 > [ 0.071107] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002 > [ 0.086103] CPU3: update cpu_capacity 448 > [ 0.086111] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003 > [ 0.101100] CPU4: update cpu_capacity 1535 > [ 0.101108] CPU4: thread -1, cpu 0, socket 0, mpidr 80000000 > [ 1.115009] CPU5: failed to boot: -110 > [ 2.130019] CPU6: failed to boot: -110 > [ 3.145049] CPU7: failed to boot: -110 > [ 3.145151] Brought up 5 CPUs > [ 3.145196] SMP: Total of 5 processors activated (240.00 BogoMIPS). > [ 3.145251] CPU: WARNING: CPU(s) started in wrong/inconsistent > modes (primary CPU mode 0x13) > [ 3.145327] CPU: This may indicate a broken bootloader or firmware. > [ 3.149347] devtmpfs: initialized > Sigh, such an inconsistent behavior between Exynos5420/5422/5800 boards :-/ Any ideas? I agree that the b.L CPUidle support shouldn't be enabled by default in exynos_defconfig but as I said nothing prevents the user to enable that option and make the board to hang on boot. > Best regards, > Krzysztof > Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/