From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756179AbaCZTu6 (ORCPT ); Wed, 26 Mar 2014 15:50:58 -0400 Received: from top.free-electrons.com ([176.31.233.9]:55176 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755633AbaCZTu4 (ORCPT ); Wed, 26 Mar 2014 15:50:56 -0400 Message-ID: <53332F99.6060805@free-electrons.com> Date: Wed, 26 Mar 2014 20:50:49 +0100 From: Gregory CLEMENT User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Fabio Estevam CC: Thomas Petazzoni , Andrew Lunn , Kevin Hilman , Mike Turquette , Jason Cooper , Arnd Bergmann , LKML , Tomasz Figa , Boris BREZILLON , Ezequiel Garcia , Olof Johansson , Shawn Guo , Sascha Hauer , linux-arm-kernel , Sebastian Hesselbarth Subject: Re: [PATCH v3] clk: respect the clock dependencies in of_clk_init References: <1393265413-16641-1-git-send-email-gregory.clement@free-electrons.com> <531068F4.3060903@free-electrons.com> <20140321035233.32624.98694@quantum> <5332FA20.4010206@free-electrons.com> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Fabio, On 26/03/2014 17:22, Fabio Estevam wrote: > Hi Gregory, > > On Wed, Mar 26, 2014 at 1:02 PM, Gregory CLEMENT > wrote: >> I don't have any imx6 board, but should it be possible for you or the imx6 >> maintainer to add earlyprintk to see exactly what happen here? > > Below is the log with earlyprintk enabled. > > Regards, > > Fabio Estevam > > Starting kernel ... > > Uncompressing Linux... done, booting the kernel. > Booting Linux on physical CPU 0x0 > Linux version 3.14.0-rc8-next-20140326 (fabio@fabio-Latitude-E6410) > (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) ) #942 SMP Wed M > ar 26 13:20:56 BRT 2014 > CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c5387d > CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache > Machine model: Wandboard i.MX6 Quad Board > bootconsole [earlycon0] enabled > Memory policy: Data cache writealloc > PERCPU: Embedded 8 pages/cpu @ee7a4000 s8960 r8192 d15616 u32768 > Built 1 zonelists in Zone order, mobility grouping on. Total pages: 520720 > Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp > nfsroot=192.168.0.2:/tftpboot/rfs,v3,tcp earlyprintk > PID hash table entries: 4096 (order: 2, 16384 bytes) > Dentry cache hash table entries: 262144 (order: 8, 1048576 bytes) > Inode-cache hash table entries: 131072 (order: 7, 524288 bytes) > Memory: 2063904K/2097152K available (6455K kernel code, 402K rwdata, > 2200K rodata, 320K init, 5513K bss, 33248K reserved, 270336K high > mem) > Virtual kernel memory layout: > vector : 0xffff0000 - 0xffff1000 ( 4 kB) > fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) > vmalloc : 0xf0000000 - 0xff000000 ( 240 MB) > lowmem : 0x80000000 - 0xef800000 (1784 MB) > pkmap : 0x7fe00000 - 0x80000000 ( 2 MB) > modules : 0x7f000000 - 0x7fe00000 ( 14 MB) > .text : 0x80008000 - 0x8087bfdc (8656 kB) > .init : 0x8087c000 - 0x808cc300 ( 321 kB) > .data : 0x808ce000 - 0x80932980 ( 403 kB) > .bss : 0x80932988 - 0x80e950f8 (5514 kB) > SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 > Hierarchical RCU implementation. > NR_IRQS:16 nr_irqs:16 16 > L310 cache controller enabled > l2x0: 16 ways, CACHE_ID 0x410000c7, AUX_CTRL 0x32070000, Cache size: 1024 kB > Switching to timer-based delay loop > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:00000000 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007e854>] (clocks_calc_mult_shift) from [<8089a8d0>] > (sched_clock_register+0x60/0x238) > r10:f0018074 r9:00000000 r8:80020ba0 r7:00000020 r6:00000000 r5:80932eac > r4:00000000 > [<8089a870>] (sched_clock_register) from [<80884588>] > (mxc_timer_init+0xf8/0x190) > r10:f0018074 r9:00000000 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac > r4:00000000 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > sched_clock: 32 bits at 0 Hz, resolution 0ns, wraps every 0ns > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee011a00 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007ea84>] (__clocksource_updatefreq_scale) from [<8007ec3c>] > (__clocksource_register_scale+0x14/0x54) > r10:000000c8 r9:00000000 r8:f0020024 r7:807b3e58 r6:ee0119c0 r5:00000000 > r4:ee011a00 > [<8007ec28>] (__clocksource_register_scale) from [<808ae6f8>] > (clocksource_mmio_init+0x8c/0xa8) > r4:ffffffff r3:00000001 > [<808ae66c>] (clocksource_mmio_init) from [<808845ac>] > (mxc_timer_init+0x11c/0x190) > r10:f0018074 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac r4:808dc900 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee011a00 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007e854>] (clocks_calc_mult_shift) from [<8007eb28>] > (__clocksource_updatefreq_scale+0xa4/0x1a4) > r10:00000001 r9:a3d70a3d r8:70a3d70a r7:0000000b r6:ee011a00 r5:00000001 > r4:00000001 > [<8007ea84>] (__clocksource_updatefreq_scale) from [<8007ec3c>] > (__clocksource_register_scale+0x14/0x54) > r10:000000c8 r9:00000000 r8:f0020024 r7:807b3e58 r6:ee0119c0 r5:00000000 > r4:ee011a00 > [<8007ec28>] (__clocksource_register_scale) from [<808ae6f8>] > (clocksource_mmio_init+0x8c/0xa8) > r4:ffffffff r3:00000001 > [<808ae66c>] (clocksource_mmio_init) from [<808845ac>] > (mxc_timer_init+0x11c/0x190) > r10:f0018074 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac r4:808dc900 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee022b80 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:808dc900 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<80082314>] (clockevents_config) from [<800823b4>] > (clockevents_config_and_register+0x1c/0x28) > r5:80932eac r4:808dc900 > [<80082398>] (clockevents_config_and_register) from [<808845d8>] > (mxc_timer_init+0x148/0x190) > r4:808dc900 r3:fffffffe > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 0 at kernel/time/clockevents.c:44 cev_delta2ns+0xe8/0x104() > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:80081cb8 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80028f78>] (warn_slowpath_common+0x70/0x94) > r5:00000009 r4:00000000 > [<80028f08>] (warn_slowpath_common) from [<80028fc0>] > (warn_slowpath_null+0x24/0x2c) > r8:000000ff r7:000000ff r6:00000000 r5:808dc900 r4:00000000 > [<80028f9c>] (warn_slowpath_null) from [<80081cb8>] (cev_delta2ns+0xe8/0x104) > [<80081bd0>] (cev_delta2ns) from [<80082374>] (clockevents_config+0x60/0x84) > r9:00000000 r8:00000057 r7:f0020024 r6:ee022b80 r5:808dc900 r4:00000000 > [<80082314>] (clockevents_config) from [<800823b4>] > (clockevents_config_and_register+0x1c/0x28) > r5:80932eac r4:808dc900 > [<80082398>] (clockevents_config_and_register) from [<808845d8>] > (mxc_timer_init+0x148/0x190) > r4:808dc900 r3:fffffffe > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > ---[ end trace 3406ff24bd97382e ]--- Thanks for the traces. As I guessed some clocks are not initialized in time. I am a bit disappointed because I tried to write a patch which in worst case didn't change this order. Viewing the code clock support for imx6, I think the problem could be due to the fact that some link between the clock are not exposed to the device tree. I need to have a closer look to sort out it. Gregory > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregory.clement@free-electrons.com (Gregory CLEMENT) Date: Wed, 26 Mar 2014 20:50:49 +0100 Subject: [PATCH v3] clk: respect the clock dependencies in of_clk_init In-Reply-To: References: <1393265413-16641-1-git-send-email-gregory.clement@free-electrons.com> <531068F4.3060903@free-electrons.com> <20140321035233.32624.98694@quantum> <5332FA20.4010206@free-electrons.com> Message-ID: <53332F99.6060805@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Fabio, On 26/03/2014 17:22, Fabio Estevam wrote: > Hi Gregory, > > On Wed, Mar 26, 2014 at 1:02 PM, Gregory CLEMENT > wrote: >> I don't have any imx6 board, but should it be possible for you or the imx6 >> maintainer to add earlyprintk to see exactly what happen here? > > Below is the log with earlyprintk enabled. > > Regards, > > Fabio Estevam > > Starting kernel ... > > Uncompressing Linux... done, booting the kernel. > Booting Linux on physical CPU 0x0 > Linux version 3.14.0-rc8-next-20140326 (fabio at fabio-Latitude-E6410) > (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) ) #942 SMP Wed M > ar 26 13:20:56 BRT 2014 > CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c5387d > CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache > Machine model: Wandboard i.MX6 Quad Board > bootconsole [earlycon0] enabled > Memory policy: Data cache writealloc > PERCPU: Embedded 8 pages/cpu @ee7a4000 s8960 r8192 d15616 u32768 > Built 1 zonelists in Zone order, mobility grouping on. Total pages: 520720 > Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp > nfsroot=192.168.0.2:/tftpboot/rfs,v3,tcp earlyprintk > PID hash table entries: 4096 (order: 2, 16384 bytes) > Dentry cache hash table entries: 262144 (order: 8, 1048576 bytes) > Inode-cache hash table entries: 131072 (order: 7, 524288 bytes) > Memory: 2063904K/2097152K available (6455K kernel code, 402K rwdata, > 2200K rodata, 320K init, 5513K bss, 33248K reserved, 270336K high > mem) > Virtual kernel memory layout: > vector : 0xffff0000 - 0xffff1000 ( 4 kB) > fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) > vmalloc : 0xf0000000 - 0xff000000 ( 240 MB) > lowmem : 0x80000000 - 0xef800000 (1784 MB) > pkmap : 0x7fe00000 - 0x80000000 ( 2 MB) > modules : 0x7f000000 - 0x7fe00000 ( 14 MB) > .text : 0x80008000 - 0x8087bfdc (8656 kB) > .init : 0x8087c000 - 0x808cc300 ( 321 kB) > .data : 0x808ce000 - 0x80932980 ( 403 kB) > .bss : 0x80932988 - 0x80e950f8 (5514 kB) > SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 > Hierarchical RCU implementation. > NR_IRQS:16 nr_irqs:16 16 > L310 cache controller enabled > l2x0: 16 ways, CACHE_ID 0x410000c7, AUX_CTRL 0x32070000, Cache size: 1024 kB > Switching to timer-based delay loop > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:00000000 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007e854>] (clocks_calc_mult_shift) from [<8089a8d0>] > (sched_clock_register+0x60/0x238) > r10:f0018074 r9:00000000 r8:80020ba0 r7:00000020 r6:00000000 r5:80932eac > r4:00000000 > [<8089a870>] (sched_clock_register) from [<80884588>] > (mxc_timer_init+0xf8/0x190) > r10:f0018074 r9:00000000 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac > r4:00000000 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > sched_clock: 32 bits at 0 Hz, resolution 0ns, wraps every 0ns > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee011a00 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007ea84>] (__clocksource_updatefreq_scale) from [<8007ec3c>] > (__clocksource_register_scale+0x14/0x54) > r10:000000c8 r9:00000000 r8:f0020024 r7:807b3e58 r6:ee0119c0 r5:00000000 > r4:ee011a00 > [<8007ec28>] (__clocksource_register_scale) from [<808ae6f8>] > (clocksource_mmio_init+0x8c/0xa8) > r4:ffffffff r3:00000001 > [<808ae66c>] (clocksource_mmio_init) from [<808845ac>] > (mxc_timer_init+0x11c/0x190) > r10:f0018074 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac r4:808dc900 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee011a00 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:00000000 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<8007e854>] (clocks_calc_mult_shift) from [<8007eb28>] > (__clocksource_updatefreq_scale+0xa4/0x1a4) > r10:00000001 r9:a3d70a3d r8:70a3d70a r7:0000000b r6:ee011a00 r5:00000001 > r4:00000001 > [<8007ea84>] (__clocksource_updatefreq_scale) from [<8007ec3c>] > (__clocksource_register_scale+0x14/0x54) > r10:000000c8 r9:00000000 r8:f0020024 r7:807b3e58 r6:ee0119c0 r5:00000000 > r4:ee011a00 > [<8007ec28>] (__clocksource_register_scale) from [<808ae6f8>] > (clocksource_mmio_init+0x8c/0xa8) > r4:ffffffff r3:00000001 > [<808ae66c>] (clocksource_mmio_init) from [<808845ac>] > (mxc_timer_init+0x11c/0x190) > r10:f0018074 r8:00000057 r7:f0020024 r6:ee022b80 r5:80932eac r4:808dc900 > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > Division by zero in kernel. > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:ee022b80 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80011a94>] (__div0+0x18/0x20) > r5:808dc900 r4:00000000 > [<80011a7c>] (__div0) from [<8029582c>] (Ldiv0_64+0x8/0x18) > [<80082314>] (clockevents_config) from [<800823b4>] > (clockevents_config_and_register+0x1c/0x28) > r5:80932eac r4:808dc900 > [<80082398>] (clockevents_config_and_register) from [<808845d8>] > (mxc_timer_init+0x148/0x190) > r4:808dc900 r3:fffffffe > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 0 at kernel/time/clockevents.c:44 cev_delta2ns+0xe8/0x104() > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc8-next-20140326 #942 > Backtrace: > [<80011cd4>] (dump_backtrace) from [<80011e70>] (show_stack+0x18/0x1c) > r6:80081cb8 r5:00000000 r4:00000000 r3:00000000 > [<80011e58>] (show_stack) from [<8064cc60>] (dump_stack+0x88/0xa4) > [<8064cbd8>] (dump_stack) from [<80028f78>] (warn_slowpath_common+0x70/0x94) > r5:00000009 r4:00000000 > [<80028f08>] (warn_slowpath_common) from [<80028fc0>] > (warn_slowpath_null+0x24/0x2c) > r8:000000ff r7:000000ff r6:00000000 r5:808dc900 r4:00000000 > [<80028f9c>] (warn_slowpath_null) from [<80081cb8>] (cev_delta2ns+0xe8/0x104) > [<80081bd0>] (cev_delta2ns) from [<80082374>] (clockevents_config+0x60/0x84) > r9:00000000 r8:00000057 r7:f0020024 r6:ee022b80 r5:808dc900 r4:00000000 > [<80082314>] (clockevents_config) from [<800823b4>] > (clockevents_config_and_register+0x1c/0x28) > r5:80932eac r4:808dc900 > [<80082398>] (clockevents_config_and_register) from [<808845d8>] > (mxc_timer_init+0x148/0x190) > r4:808dc900 r3:fffffffe > [<80884490>] (mxc_timer_init) from [<808910b0>] > (imx6q_clocks_init+0x2c00/0x2d24) > r8:00000004 r7:809334d0 r6:808c7310 r5:ee7ccbe8 r4:f0020000 > [<8088e4b0>] (imx6q_clocks_init) from [<808b024c>] (of_clk_init+0xd8/0x198) > r10:80923594 r9:809234d4 r8:00000000 r7:ee002ac0 r6:ee002b00 r5:ee7ce5b0 > r4:00000001 > [<808b0174>] (of_clk_init) from [<80880364>] (time_init+0x2c/0x38) > r10:ef7fc9c0 r9:412fc09a r8:808d6880 r7:808bd790 r6:ffffffff r5:809329c0 > r4:00000001 > [<80880338>] (time_init) from [<8087ca2c>] (start_kernel+0x1f8/0x388) > [<8087c834>] (start_kernel) from [<10008074>] (0x10008074) > r10:00000000 r8:1000406a r7:808db644 r6:808bd78c r5:808d692c r4:10c5387d > ---[ end trace 3406ff24bd97382e ]--- Thanks for the traces. As I guessed some clocks are not initialized in time. I am a bit disappointed because I tried to write a patch which in worst case didn't change this order. Viewing the code clock support for imx6, I think the problem could be due to the fact that some link between the clock are not exposed to the device tree. I need to have a closer look to sort out it. Gregory > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com