[PATCH linux dev-5.4 v2] ARM: aspeed: ast2600: Select timer

[PATCH linux dev-5.4 v2] ARM: aspeed: ast2600: Select timer

[Eddie James]

The AST2600 also uses the FTTMR010.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
Changes since v1:
 - Add back HAVE_ARM_ARCH_TIMER which is apparently necessary to boot...

 arch/arm/mach-aspeed/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/mach-aspeed/Kconfig b/arch/arm/mach-aspeed/Kconfig
index 693cbdd..129bc19 100644
--- a/arch/arm/mach-aspeed/Kconfig
+++ b/arch/arm/mach-aspeed/Kconfig
@@ -39,6 +39,7 @@ config MACH_ASPEED_G6
 	select CPU_V7
 	select PINCTRL_ASPEED_G6
 	select ARM_GIC
+	select FTTMR010_TIMER
 	select HAVE_ARM_ARCH_TIMER
 	select HAVE_SMP
 	help
-- 
1.8.3.1

Re: [PATCH linux dev-5.4 v2] ARM: aspeed: ast2600: Select timer

[Joel Stanley]

On Wed, 25 Mar 2020 at 21:26, Eddie James <eajames@linux.ibm.com> wrote:
>
> The AST2600 also uses the FTTMR010.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
> Changes since v1:
>  - Add back HAVE_ARM_ARCH_TIMER which is apparently necessary to boot...

We want to use the arch timer. Aspeed recommends not having the
fttmr010 driver loaded at all, and just using the arch timer. The
problem with that is the kernel decides that it can't enable hrtimers
with just the arch timer, so in the past I was working around that by
enabling the fttmr010.

Another possibility is to use the always-on property in the device tree:

Documentation/devicetree/bindings/timer/arm,arch_timer.yaml

  always-on:
    type: boolean
    description: If present, the timer is powered through an always-on power
      domain, therefore it never loses context.

Can you test adding this, but having fttmr010 disabled?

Cheers,

Joel

>
>  arch/arm/mach-aspeed/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/mach-aspeed/Kconfig b/arch/arm/mach-aspeed/Kconfig
> index 693cbdd..129bc19 100644
> --- a/arch/arm/mach-aspeed/Kconfig
> +++ b/arch/arm/mach-aspeed/Kconfig
> @@ -39,6 +39,7 @@ config MACH_ASPEED_G6
>         select CPU_V7
>         select PINCTRL_ASPEED_G6
>         select ARM_GIC
> +       select FTTMR010_TIMER
>         select HAVE_ARM_ARCH_TIMER
>         select HAVE_SMP
>         help
> --
> 1.8.3.1
>

Re: [PATCH linux dev-5.4 v2] ARM: aspeed: ast2600: Select timer

[Eddie James]

On 3/25/20 4:56 PM, Joel Stanley wrote:
> On Wed, 25 Mar 2020 at 21:26, Eddie James <eajames@linux.ibm.com> wrote:
>> The AST2600 also uses the FTTMR010.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> ---
>> Changes since v1:
>>   - Add back HAVE_ARM_ARCH_TIMER which is apparently necessary to boot...
> We want to use the arch timer. Aspeed recommends not having the
> fttmr010 driver loaded at all, and just using the arch timer. The
> problem with that is the kernel decides that it can't enable hrtimers
> with just the arch timer, so in the past I was working around that by
> enabling the fttmr010.
>
> Another possibility is to use the always-on property in the device tree:
>
> Documentation/devicetree/bindings/timer/arm,arch_timer.yaml
>
>    always-on:
>      type: boolean
>      description: If present, the timer is powered through an always-on power
>        domain, therefore it never loses context.
>
> Can you test adding this, but having fttmr010 disabled?


Ah, I see. Yes I will test that.

Thanks for explaining!

Eddie


>
> Cheers,
>
> Joel
>
>>   arch/arm/mach-aspeed/Kconfig | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/mach-aspeed/Kconfig b/arch/arm/mach-aspeed/Kconfig
>> index 693cbdd..129bc19 100644
>> --- a/arch/arm/mach-aspeed/Kconfig
>> +++ b/arch/arm/mach-aspeed/Kconfig
>> @@ -39,6 +39,7 @@ config MACH_ASPEED_G6
>>          select CPU_V7
>>          select PINCTRL_ASPEED_G6
>>          select ARM_GIC
>> +       select FTTMR010_TIMER
>>          select HAVE_ARM_ARCH_TIMER
>>          select HAVE_SMP
>>          help
>> --
>> 1.8.3.1
>>