Messages in this thread | | | Date | Thu, 07 Nov 2019 20:57:58 +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 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.
> >>>> + 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 >
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