2016-03-01 14:52:51

by Peter Hurley

Subject: Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
> SBBR mentions DBG2 as a mandatory ACPI table.
> So enable it for ARM64

Why does this have to be opted-in per-arch?


> Signed-off-by: Aleksey Makarov <[email protected]>
> ---
> arch/arm64/Kconfig | 1 +
> arch/arm64/kernel/acpi.c | 2 ++
> 2 files changed, 3 insertions(+)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 9dc5209..0b614d4 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -3,6 +3,7 @@ config ARM64
> select ACPI_CCA_REQUIRED if ACPI
> select ACPI_GENERIC_GSI if ACPI
> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
> + select ACPI_DBG2_TABLE if ACPI
> select ARCH_HAS_DEVMEM_IS_ALLOWED
> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> select ARCH_HAS_ELF_RANDOMIZE
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index d1ce8e2..3370046 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
> pr_err("Failed to init ACPI tables\n");
> if (!param_acpi_force)
> disable_acpi();
> + } else {
> + acpi_probe_device_table(dbg2);
> }
> }
>
>

2016-03-01 17:03:52

by Aleksey Makarov

Subject: Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

On 03/01/2016 05:52 PM, Peter Hurley wrote:
> On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
>> SBBR mentions DBG2 as a mandatory ACPI table.
>> So enable it for ARM64
>
> Why does this have to be opted-in per-arch?

DBG2 can specify earlycons. They should start as soon as possible.
On ARM64 it is just after boot tables become available (in arch_init()).
So it has to be per-arch unless we decide not to start earlycons on
DBG2 ports.

>> Signed-off-by: Aleksey Makarov <[email protected]>
>> ---
>> arch/arm64/Kconfig | 1 +
>> arch/arm64/kernel/acpi.c | 2 ++
>> 2 files changed, 3 insertions(+)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 9dc5209..0b614d4 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -3,6 +3,7 @@ config ARM64
>> select ACPI_CCA_REQUIRED if ACPI
>> select ACPI_GENERIC_GSI if ACPI
>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>> + select ACPI_DBG2_TABLE if ACPI
>> select ARCH_HAS_DEVMEM_IS_ALLOWED
>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>> select ARCH_HAS_ELF_RANDOMIZE
>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>> index d1ce8e2..3370046 100644
>> --- a/arch/arm64/kernel/acpi.c
>> +++ b/arch/arm64/kernel/acpi.c
>> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
>> pr_err("Failed to init ACPI tables\n");
>> if (!param_acpi_force)
>> disable_acpi();
>> + } else {
>> + acpi_probe_device_table(dbg2);
>> }
>> }
>>
>>
>

2016-03-01 17:25:46

by Peter Hurley

Subject: Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

On 03/01/2016 09:02 AM, Aleksey Makarov wrote:
>
>
> On 03/01/2016 05:52 PM, Peter Hurley wrote:
>> On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
>>> SBBR mentions DBG2 as a mandatory ACPI table.
>>> So enable it for ARM64
>>
>> Why does this have to be opted-in per-arch?
>
> DBG2 can specify earlycons. They should start as soon as possible.
> On ARM64 it is just after boot tables become available (in arch_init()).
> So it has to be per-arch unless we decide not to start earlycons on
> DBG2 ports.

OF does all that already but the earlycon opt-in is not per-arch.


>>> Signed-off-by: Aleksey Makarov <[email protected]>
>>> ---
>>> arch/arm64/Kconfig | 1 +
>>> arch/arm64/kernel/acpi.c | 2 ++
>>> 2 files changed, 3 insertions(+)
>>>
>>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>>> index 9dc5209..0b614d4 100644
>>> --- a/arch/arm64/Kconfig
>>> +++ b/arch/arm64/Kconfig
>>> @@ -3,6 +3,7 @@ config ARM64
>>> select ACPI_CCA_REQUIRED if ACPI
>>> select ACPI_GENERIC_GSI if ACPI
>>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>>> + select ACPI_DBG2_TABLE if ACPI
>>> select ARCH_HAS_DEVMEM_IS_ALLOWED
>>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>>> select ARCH_HAS_ELF_RANDOMIZE
>>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>>> index d1ce8e2..3370046 100644
>>> --- a/arch/arm64/kernel/acpi.c
>>> +++ b/arch/arm64/kernel/acpi.c
>>> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
>>> pr_err("Failed to init ACPI tables\n");
>>> if (!param_acpi_force)
>>> disable_acpi();
>>> + } else {
>>> + acpi_probe_device_table(dbg2);
>>> }
>>> }
>>>
>>>
>>

2016-03-03 11:42:24

by Aleksey Makarov

Subject: Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

On 03/01/2016 08:25 PM, Peter Hurley wrote:
> On 03/01/2016 09:02 AM, Aleksey Makarov wrote:
>>
>>
>> On 03/01/2016 05:52 PM, Peter Hurley wrote:
>>> On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
>>>> SBBR mentions DBG2 as a mandatory ACPI table.
>>>> So enable it for ARM64
>>>
>>> Why does this have to be opted-in per-arch?
>>
>> DBG2 can specify earlycons. They should start as soon as possible.
>> On ARM64 it is just after boot tables become available (in arch_init()).
>> So it has to be per-arch unless we decide not to start earlycons on
>> DBG2 ports.
>
> OF does all that already but the earlycon opt-in is not per-arch.

In the last next-XXXX kernel support for OF earlycon depends on
CONFIG_OF_EARLY_FLATTREE which *is* per-arch.

Probably we need the same kind of configuration option here,
something like CONFIG_ACPI_BOOT_TABLES instead of ACPI_DBG2_TABLE.

>>>> Signed-off-by: Aleksey Makarov <[email protected]>
>>>> ---
>>>> arch/arm64/Kconfig | 1 +
>>>> arch/arm64/kernel/acpi.c | 2 ++
>>>> 2 files changed, 3 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>>>> index 9dc5209..0b614d4 100644
>>>> --- a/arch/arm64/Kconfig
>>>> +++ b/arch/arm64/Kconfig
>>>> @@ -3,6 +3,7 @@ config ARM64
>>>> select ACPI_CCA_REQUIRED if ACPI
>>>> select ACPI_GENERIC_GSI if ACPI
>>>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>>>> + select ACPI_DBG2_TABLE if ACPI
>>>> select ARCH_HAS_DEVMEM_IS_ALLOWED
>>>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>>>> select ARCH_HAS_ELF_RANDOMIZE
>>>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>>>> index d1ce8e2..3370046 100644
>>>> --- a/arch/arm64/kernel/acpi.c
>>>> +++ b/arch/arm64/kernel/acpi.c
>>>> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
>>>> pr_err("Failed to init ACPI tables\n");
>>>> if (!param_acpi_force)
>>>> disable_acpi();
>>>> + } else {
>>>> + acpi_probe_device_table(dbg2);
>>>> }
>>>> }
>>>>
>>>>
>>>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

2016-03-03 15:51:57

by Peter Hurley

Subject: Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

On 03/03/2016 03:41 AM, Aleksey Makarov wrote:
>
>
> On 03/01/2016 08:25 PM, Peter Hurley wrote:
>> On 03/01/2016 09:02 AM, Aleksey Makarov wrote:
>>>
>>>
>>> On 03/01/2016 05:52 PM, Peter Hurley wrote:
>>>> On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
>>>>> SBBR mentions DBG2 as a mandatory ACPI table.
>>>>> So enable it for ARM64
>>>>
>>>> Why does this have to be opted-in per-arch?
>>>
>>> DBG2 can specify earlycons. They should start as soon as possible.
>>> On ARM64 it is just after boot tables become available (in arch_init()).
>>> So it has to be per-arch unless we decide not to start earlycons on
>>> DBG2 ports.
>>
>> OF does all that already but the earlycon opt-in is not per-arch.
>
> In the last next-XXXX kernel support for OF earlycon depends on
> CONFIG_OF_EARLY_FLATTREE which *is* per-arch.

That's true.

(of_setup_earlycon() was really always CONFIG_OF_EARLY_FLATTREE because
its lone caller was CONFIG_OF_EARLY_FLATTREE).


> Probably we need the same kind of configuration option here,
> something like CONFIG_ACPI_BOOT_TABLES instead of ACPI_DBG2_TABLE.

I'll let acpi maintainers sort that.


>>>>> Signed-off-by: Aleksey Makarov <[email protected]>
>>>>> ---
>>>>> arch/arm64/Kconfig | 1 +
>>>>> arch/arm64/kernel/acpi.c | 2 ++
>>>>> 2 files changed, 3 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>>>>> index 9dc5209..0b614d4 100644
>>>>> --- a/arch/arm64/Kconfig
>>>>> +++ b/arch/arm64/Kconfig
>>>>> @@ -3,6 +3,7 @@ config ARM64
>>>>> select ACPI_CCA_REQUIRED if ACPI
>>>>> select ACPI_GENERIC_GSI if ACPI
>>>>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>>>>> + select ACPI_DBG2_TABLE if ACPI
>>>>> select ARCH_HAS_DEVMEM_IS_ALLOWED
>>>>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>>>>> select ARCH_HAS_ELF_RANDOMIZE
>>>>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>>>>> index d1ce8e2..3370046 100644
>>>>> --- a/arch/arm64/kernel/acpi.c
>>>>> +++ b/arch/arm64/kernel/acpi.c
>>>>> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
>>>>> pr_err("Failed to init ACPI tables\n");
>>>>> if (!param_acpi_force)
>>>>> disable_acpi();
>>>>> + } else {
>>>>> + acpi_probe_device_table(dbg2);
>>>>> }
>>>>> }
>>>>>
>>>>>
>>>>
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> [email protected]
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>