Messages in this thread | | | Date | Thu, 07 Nov 2019 21:34:29 +0100 | From | Paul Cercueil <> | Subject | Re: [PATCH] clocksource: Add driver for the Ingenic JZ47xx OST |
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Le jeu., nov. 7, 2019 at 21:22, Daniel Lezcano <daniel.lezcano@linaro.org> a écrit : > On 07/11/2019 20:57, Paul Cercueil wrote: >> >> >> Le jeu., nov. 7, 2019 at 20:39, Daniel Lezcano >> <daniel.lezcano@linaro.org> a écrit : >>> On 07/11/2019 16:56, Paul Cercueil wrote: >>>> Hi Daniel, >>>> >>>> On 2019-08-16 16:54, Daniel Lezcano wrote: >>>>> On 09/08/2019 14:38, Paul Cercueil wrote: >>>>>> From: Maarten ter Huurne <maarten@treewalker.org> >>>>>> >>>>>> OST is the OS Timer, a 64-bit timer/counter with buffered >>>>>> reading. >>>>>> >>>>>> SoCs before the JZ4770 had (if any) a 32-bit OST; the JZ4770 >>>>>> and >>>>>> JZ4780 have a 64-bit OST. >>>>>> >>>>>> This driver will register both a clocksource and a sched_clock >>>>>> to the >>>>>> system. >>>>>> >>>>>> Signed-off-by: Maarten ter Huurne <maarten@treewalker.org> >>>>>> Signed-off-by: Paul Cercueil <paul@crapouillou.net> >>>>>> Tested-by: Mathieu Malaterre <malat@debian.org> >>>>>> Tested-by: Artur Rojek <contact@artur-rojek.eu> >>>>>> --- >>>>>> >>>>> >>>>> [ ... ] >>>>> >>>>>> + err = clocksource_register_hz(cs, rate); >>>>>> + if (err) { >>>>>> + dev_err(dev, "clocksource registration failed: %d\n", >>>>>> err); >>>>>> + clk_disable_unprepare(ost->clk); >>>>>> + return err; >>>>>> + } >>>>>> + >>>>>> + /* Cannot register a sched_clock with interrupts on */ >>>>> >>>>> Aren't they already disabled? >>>> >>>> Sorry for the late reply. >>>> >>>> No, they are not already disabled; this is what I get if I >>>> comment out >>>> the local_irq_save()/local_irq_restore(): >>>> >>>> [ 0.361014] clocksource: ingenic-ost: mask: 0xffffffff >>>> max_cycles: >>>> 0xffffffff, max_idle_ns: 159271703898 ns >>>> [ 0.361515] clocksource: Switched to clocksource ingenic-ost >>>> [ 0.361686] ------------[ cut here ]------------ >>>> [ 0.361893] WARNING: CPU: 0 PID: 1 at >>>> kernel/time/sched_clock.c:179 >>>> sched_clock_register+0x7c/0x2e4 >>>> [ 0.362174] CPU: 0 PID: 1 Comm: swapper Not tainted >>>> 5.4.0-rc5+ #461 >>>> [ 0.362330] Stack : 80744558 80069b44 80770000 00000000 >>>> 00000000 >>>> 00dfd7a7 806e6db4 8106bb74 >>>> [ 0.362619] 806f0000 81067ca4 806f31c7 80769478 >>>> 00000020 >>>> 10000400 8106bb20 00dfd7a7 >>>> [ 0.362906] 00000000 00000000 80780000 00000000 >>>> 00000007 >>>> 00000001 00000049 3563722d >>>> [ 0.363191] 8106ba61 00000000 ffffffff 00000010 >>>> 806f0000 >>>> 00000000 00000000 806f0000 >>>> [ 0.363477] 00000020 00000000 80714534 80770000 >>>> 00000002 >>>> 80319154 00000000 80770000 >>>> [ 0.363762] ... >>>> [ 0.363906] Call Trace: >>>> [ 0.364087] [<8001af14>] show_stack+0x40/0x128 >>>> [ 0.364289] [<8002fd88>] __warn+0xb8/0xe0 >>>> [ 0.364478] [<8002fe14>] warn_slowpath_fmt+0x64/0xc0 >>>> [ 0.364678] [<8072b1c8>] sched_clock_register+0x7c/0x2e4 >>>> [ 0.364895] [<8073c874>] ingenic_ost_probe+0x224/0x248 >>>> [ 0.365090] [<803d5394>] platform_drv_probe+0x40/0x94 >>>> [ 0.365526] [<803d362c>] really_probe+0x104/0x374 >>>> [ 0.365743] [<803d3ff0>] device_driver_attach+0x78/0x80 >>>> [ 0.365938] [<803d4070>] __driver_attach+0x78/0x118 >>>> [ 0.366129] [<803d1700>] bus_for_each_dev+0x7c/0xc8 >>>> [ 0.366318] [<803d226c>] bus_add_driver+0x1bc/0x204 >>>> [ 0.366513] [<803d4878>] driver_register+0x84/0x14c >>>> [ 0.366717] [<8073a144>] __platform_driver_probe+0x98/0x140 >>>> [ 0.366931] [<80724e38>] do_one_initcall+0x84/0x1b4 >>>> [ 0.367126] [<807250cc>] kernel_init_freeable+0x164/0x240 >>>> [ 0.367318] [<805df75c>] kernel_init+0x10/0xf8 >>>> [ 0.367510] [<8001542c>] ret_from_kernel_thread+0x14/0x1c >>>> [ 0.367722] ---[ end trace 7fedf00408fa3bed ]--- >>>> [ 0.367985] sched_clock: 32 bits at 12MHz, resolution 83ns, >>>> wraps >>>> every 178956970966ns >>>> >>>> At kernel/time/sched_clock.c:179 there is: >>>> WARN_ON(!irqs_disabled()); >>> >>> That is strange, no drivers is doing that and no warning is >>> appearing. >>> >>> Isn't missing a local_irq_disable in the code path in the stack >>> above? >> >> I think it comes to the fact that the other drivers are probed much >> earlier in the boot process, while this one is probed as a regular >> platform device driver. > > > There are other drivers doing and nobody is disabling the interrupt: > > em_sti.c:static struct platform_driver em_sti_device_driver = { > ingenic-timer.c:static struct platform_driver ingenic_tcu_driver = { > sh_cmt.c:static struct platform_driver sh_cmt_device_driver = { > sh_mtu2.c:static struct platform_driver sh_mtu2_device_driver = { > sh_tmu.c:static struct platform_driver sh_tmu_device_driver = { > timer-ti-dm.c:static struct platform_driver omap_dm_timer_driver = {
Yes, but they don't register a sched_clock at all (except for ingenic-timer, but it does probe using TIMER_OF_DECLARE), and this warning is in sched_clock_register().
> >>>>>> + local_irq_save(flags); >>>>>> + if (soc_info->is64bit) >>>>>> + sched_clock_register(ingenic_ost_read_cntl, 32, rate); >>>>>> + else >>>>>> + sched_clock_register(ingenic_ost_read_cnth, 32, rate); >>>>>> + local_irq_restore(flags); >>>>>> + >>>>>> + return 0; >>>>>> +} >>>>>> + >>> >>> >>> -- >>> <http://www.linaro.org/> Linaro.org │ Open source software for >>> ARM SoCs >>> >>> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | >>> <http://twitter.com/#!/linaroorg> Twitter | >>> <http://www.linaro.org/linaro-blog/> Blog >>> >> >> > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM > SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog >
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