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Groups > linux.kernel > #1562690
| From | Hanjun Guo <hanjun.guo@linaro.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. |
| Date | 2017-01-19 13:50 +0100 |
| Message-ID | <t1kka-1B7-13@gated-at.bofh.it> (permalink) |
| References | <t0Ytk-4D1-15@gated-at.bofh.it> <t0YD1-4Gk-45@gated-at.bofh.it> <t1fXb-7pT-5@gated-at.bofh.it> <t1hvX-8e7-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 2017/1/19 17:44, Fu Wei wrote:
> Hi Hanjun,
>
> On 19 January 2017 at 16:02, Hanjun Guo <hanjun.guo@linaro.org> wrote:
>> Hi Fuwei,
>>
>> One comments below.
>>
>>
>> On 2017/1/18 21:25, fu.wei@linaro.org wrote:
>>>
>>> From: Fu Wei <fu.wei@linaro.org>
>>>
>>> The counter frequency detection call(arch_timer_detect_rate) combines two
>>> ways to get counter frequency: system coprocessor register and MMIO timer.
>>> But in a specific timer init code, we only need one way to try:
>>> getting frequency from MMIO timer register will be needed only when we
>>> init MMIO timer; getting frequency from system coprocessor register will
>>> be needed only when we init arch timer.
>>>
>>> This patch separates paths to determine frequency:
>>> Separate out the MMIO frequency and the sysreg frequency detection call,
>>> and use the appropriate one for the counter.
>>>
>>> Signed-off-by: Fu Wei <fu.wei@linaro.org>
>>> ---
>>> drivers/clocksource/arm_arch_timer.c | 40
>>> ++++++++++++++++++++++--------------
>>> 1 file changed, 25 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/clocksource/arm_arch_timer.c
>>> b/drivers/clocksource/arm_arch_timer.c
>>> index 6484f84..9482481 100644
>>> --- a/drivers/clocksource/arm_arch_timer.c
>>> +++ b/drivers/clocksource/arm_arch_timer.c
>>> @@ -488,23 +488,33 @@ static int arch_timer_starting_cpu(unsigned int cpu)
>>> return 0;
>>> }
>>>
>>> -static void arch_timer_detect_rate(void __iomem *cntbase)
>>> +static void __arch_timer_determine_rate(u32 rate)
>>> {
>>> - /* Who has more than one independent system counter? */
>>> - if (arch_timer_rate)
>>> - return;
>>> + /* Check the timer frequency. */
>>> + if (!arch_timer_rate) {
>>> + if (rate)
>>> + arch_timer_rate = rate;
>>> + else
>>> + pr_warn("frequency not available\n");
>>> + } else if (rate && arch_timer_rate != rate) {
>>
>> ^
>> Typo? I think it's "&" here.
>
> Not a typo, It's definitely a “&&” :-)
>
> Here arch_timer_rate is not zero.
>
> If rate is not zero(that means we got a valid rate), and
> arch_timer_rate != rate ,
> we will print warning message.
Ah, misreading the code, thanks for clarify :)
Hanjun
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[PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 01/17] clocksource/drivers/arm_arch_timer: Improve printk relevant code fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 02/17] clocksource/drivers/arm_arch_timer: Rename the timer type macros. fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 06/17] clocksource/drivers/arm_arch_timer: rework PPI determination fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 12/17] clocksource/drivers/arm_arch_timer: Refactor MMIO timer probing. fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:20 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:10 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 13:50 +0100
[PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 09:30 +0100
Re: [PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:00 +0100
[PATCH v20 07/17] clocksource/drivers/arm_arch_timer: Separate out device-tree code from arch_timer_detect_rate fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 09/17] clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:20 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:40 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Mark Rutland <mark.rutland@arm.com> - 2017-01-19 12:20 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Fu Wei <fu.wei@linaro.org> - 2017-01-19 13:30 +0100
[PATCH v20 05/17] clocksource/drivers/arm_arch_timer: Add a new enum for spi type fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 09:10 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-19 10:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 13:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-24 18:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-25 07:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-25 08:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Christopher Covington <cov@codeaurora.org> - 2017-01-25 16:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-25 18:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-26 07:00 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-25 18:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-26 06:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-30 19:00 +0100
[PATCH v20 10/17] clocksource/drivers/arm_arch_timer: Move arch_timer_needs_of_probing into DT init call fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 14/17] clocksource/drivers/arm_arch_timer: Simplify ACPI support code. fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 15/17] acpi/arm64: Add memory-mapped timer support in GTDT driver fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 17/17] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver fu.wei@linaro.org - 2017-01-18 14:50 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:30 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Fu Wei <fu.wei@linaro.org> - 2017-01-19 12:20 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Mark Rutland <mark.rutland@arm.com> - 2017-01-23 20:00 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Fu Wei <fu.wei@linaro.org> - 2017-01-24 06:20 +0100
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