Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1562451

Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection.

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 09:10 +0100
Message-ID <t1fXb-7pT-5@gated-at.bofh.it> (permalink)
References <t0Ytk-4D1-15@gated-at.bofh.it> <t0YD1-4Gk-45@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


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.

Thanks
Hanjun

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[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

csiph-web