Messages in this thread Patch in this message | | | Date | Sat, 18 Jul 2020 18:11:10 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH v6 2/2] clocksource: Ingenic: Add support for the Ingenic X1000 OST. |
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Le sam. 18 juil. 2020 à 23:55, Zhou Yanjie <zhouyanjie@wanyeetech.com> a écrit : > Hi Paul, > > 在 2020/7/18 下午11:44, Paul Cercueil 写道: >> Hi Zhou, >> >> Le sam. 18 juil. 2020 à 21:42, Zhou Yanjie >> <zhouyanjie@wanyeetech.com> a écrit : >>> Hello Paul and Daniel, >>> >>> 在 2020/7/18 下午9:12, Paul Cercueil 写道: >>>> Hi Daniel, >>>> >>>> Le ven. 17 juil. 2020 à 10:02, Daniel Lezcano >>>> <daniel.lezcano@linaro.org> a écrit : >>>>> On 17/07/2020 08:13, Zhou Yanjie wrote: >>>>>> Hi Daniel, >>>>>> >>>>>> 在 2020/7/17 下午12:20, Daniel Lezcano 写道: >>>>>>> On 10/07/2020 19:02, 周琰杰 (Zhou Yanjie) wrote: >>>>>>>> X1000 and SoCs after X1000 (such as X1500 and X1830) had a >>>>>>>> separate >>>>>>>> OST, it no longer belongs to TCU. This driver will register >>>>>>>> both a >>>>>>>> clocksource and a sched_clock to the system. >>>>>>>> >>>>>>>> Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com> >>>>>>>> Co-developed-by: 漆鹏振 (Qi Pengzhen) >>>>>>>> <aric.pzqi@ingenic.com> >>>>>>>> Signed-off-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com> >>>>>>>> Signed-off-by: 周琰杰 (Zhou Yanjie) >>>>>>>> <zhouyanjie@wanyeetech.com> >>>>>>>> Reviewed-by: Paul Cercueil <paul@crapouillou.net> >>>>>>>> --- >>>>>>>> >>>>>>>> Notes: >>>>>>>> v1->v2: >>>>>>>> Fix compile warnings. >>>>>>>> Reported-by: kernel test robot <lkp@intel.com> >>>>>>>> v2->v3: >>>>>>>> No change. >>>>>>>> v3->v4: >>>>>>>> 1.Rename "ost" to "sysost" >>>>>>>> 1.Remove unrelated changes. >>>>>>>> 2.Remove ost_clock_parent enum. >>>>>>>> 3.Remove >>>>>>>> ost->percpu_timer_channel/ost->global_timer_channel. >>>>>>>> 4.Set up independent .recalc_rate/.set_rate for >>>>>>>> percpu/global >>>>>>>> timer. >>>>>>>> 5.No longer call functions in variable declarations. >>>>>>>> v4->v5: >>>>>>>> Use "of_io_request_and_map()" instead "of_iomap()". >>>>>>>> Suggested-by: Paul Cercueil <paul@crapouillou.net> >>>>>>>> v5->v6: >>>>>>>> No change. >>>>>>>> >>>>>>>> drivers/clocksource/Kconfig | 11 + >>>>>>>> drivers/clocksource/Makefile | 1 + >>>>>>>> drivers/clocksource/ingenic-sysost.c | 539 >>>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>>> 3 files changed, 551 insertions(+) >>>>>>>> create mode 100644 drivers/clocksource/ingenic-sysost.c >>>>>>>> >>>>>>>> diff --git a/drivers/clocksource/Kconfig >>>>>>>> b/drivers/clocksource/Kconfig >>>>>>>> index 91418381fcd4..1bca8b8fb30f 100644 >>>>>>>> --- a/drivers/clocksource/Kconfig >>>>>>>> +++ b/drivers/clocksource/Kconfig >>>>>>>> @@ -696,6 +696,17 @@ config INGENIC_TIMER >>>>>>>> help >>>>>>>> Support for the timer/counter unit of the Ingenic JZ >>>>>>>> SoCs. >>>>>>>> +config INGENIC_SYSOST >>>>>>>> + bool "Clocksource/timer using the SYSOST in Ingenic X >>>>>>>> SoCs" >>>>>>> We usually use silent options and let the platform's Kconfig >>>>>>> enable it. >>>>>>> We show up the option only when COMPILE_TEST is enabled. >>>>>>> >>>>>>> Is there a reason to do it differently? >>>>>> >>>>>> >>>>>> Do you mean >>>>>> >>>>>> bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" >>>>>> >>>>>> or >>>>>> >>>>>> default MACH_INGENIC ? >>>>> >>>>> Both, no default here. >>>>> >>>>> eg. >>>>> >>>>> bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" if >>>>> COMPILE_TEST >>>>> >>>>> and >>>>> >>>>> in arch/mips/Kconfig in the config MACH_INGENIC section : >>>>> >>>>> ... >>>>> select INGENIC_SYSOST >>>>> ... >>>> >>>> Disagreed. That's not how we do things on MIPS. Selecting >>>> MACH_INGENIC means "this kernel will support Ingenic SoCs", >>>> but not that it will only support these. Hence the depends on >>>> MIPS / default MACH_INGENIC. >>>> >>>> As for the select INGENIC_SYSOST, this driver only applies to a >>>> few SoCs, I certainly don't want it to be force-enabled. I >>>> don't even wait it to be force-enabled on X1000, since it is >>>> optional there too. >>>> >>>> Cheers, >>>> -Paul >>> >>> >>> If we still need to keep the "default MACH_INGENIC", then Daniel >>> can directly apply the v6 version. >>> >>> If we need to use the silent options, maybe we can enable them >>> separately according to >>> MACH_JZ4740/MACH_JZ4770/MACH_JZ4780/MACH_X1000/MACH_X1830. >>> >>> In fact, I think X1000 and X1830 need to enable this driver in most >>> cases, because the current test has found that use TCU to provide >>> clocksource and clockevent will cause data loss/error when >>> transmitting data through spi or ethernet. And these errors no >>> longer appear after using OST. >> >> This is likely because the clock is too fast, try to reduce it by a >> factor 2 or 4, it should behave better. >> > > Yes, it is indeed because the clock is too fast, especially the TCU > only has 16-bit, which makes this problem more serious. I even > reduced the timing clock to the lowest possible 23kHz (divided by > 1024). The problem has been alleviated, but it cannot completely > solved, and finally there is no problem after opening the OST. > > >> If it turns out OST is really needed, then it should be selected >> from MACH_X1000/X1830, not MACH_INGENIC. >> > > Sure, I will do it in v8. > > Thanks and best regards!
Please do it in a separate patch then (but in the same patchset).
Cheers, -Paul
> >> Cheers, >> -Paul >> >>> Thanks and best regards! >>> >>> >>>> >>>>> >>>>>> This driver has some origins from "INGENIC_TIMER" driver and >>>>>> "INGENIC_OST" driver. >>>>>> Early Ingenic processors used TCU (timer/counter unit, has 6 or >>>>>> 8 >>>>>> generic timer channels) to provide clocksource and clockevent >>>>>> (both with >>>>>> only 16bit precision). This part of the processor can only use >>>>>> "INGENIC_TIMER" driver. >>>>>> >>>>>> Later processors provide an independent 32bit or 64bit timer >>>>>> channel >>>>>> (still under TCU, known as ost channel, this channel can not >>>>>> generate >>>>>> interrupt) to provid higher precision clocksource. The >>>>>> "INGENIC_OST" >>>>>> driver is for this channel. These processors can use >>>>>> "INGENIC_TIMER" >>>>>> driver, but using "INGENIC_OST" driver to provide higher >>>>>> precision >>>>>> clocksource would be a better choice (clockevent still needs to >>>>>> be >>>>>> provided by generic timer channel of TCU, and still 16bit >>>>>> precision). >>>>>> >>>>>> And the recent processors provide a SYSOST components, it is >>>>>> independent >>>>>> from TCU, including a 64bit timer channel for clocksource and a >>>>>> 32bit >>>>>> timer channel for clockevent. Although these processors can >>>>>> also use >>>>>> "INGENIC_TIMER" driver, but the better choice is completely >>>>>> independent >>>>>> use of "INGENIC_SYSOST" driver to provide higher precision >>>>>> clocksource >>>>>> and clockevent. >>>>> >>>>> Ok, the rating should do the job then. >>>>> >>>>> Thanks for the explanation. >>>>> >>>>>> You may have already noticed that this independent SYSOST >>>>>> component is >>>>>> like an upgraded and streamlined TCU, which only retains one >>>>>> generic >>>>>> timer channel that can generate interrupts, upgrade it from >>>>>> 16bit to >>>>>> 32bit, and then retain the 64bit ost channel. so the driver >>>>>> code and >>>>>> Kconfig code of this patch is largely referenced >>>>>> "INGENIC_TIMER" driver and "INGENIC_OST" driver. >>>>>> >>>>>> Thanks and best regards! >>>>>> >>>>>>>> + default MACH_INGENIC >>>>>>>> + depends on MIPS || COMPILE_TEST >>>>>>>> + depends on COMMON_CLK >>>>>>>> + select MFD_SYSCON >>>>>>>> + select TIMER_OF >>>>>>>> + select IRQ_DOMAIN >>>>>>>> + help >>>>>>>> + Support for the SYSOST of the Ingenic X Series SoCs. >>>>>>>> + >>>>>>> [ ... ] >>>>>>> >>>>>>> >>>>> >>>>> >>>>> -- >>>>> <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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