Re: [PATCH v2 4/5] acpi: Enable TPM IRQ

[Stefan Berger <stefanb@linux.ibm.com>]

On 6/16/20 9:01 AM, Auger Eric wrote:
> Hi Stefan,
>
> On 6/15/20 7:11 PM, Stefan Berger wrote:
>> On 6/15/20 11:13 AM, Marc-André Lureau wrote:
>>>> diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
>>>> index 1a2a57a21f..063a9eb42a 100644
>>>> --- a/include/hw/acpi/tpm.h
>>>> +++ b/include/hw/acpi/tpm.h
>>>> @@ -24,7 +24,7 @@
>>>>    #define TPM_TIS_ADDR_BASE           0xFED40000
>>>>    #define TPM_TIS_ADDR_SIZE           0x5000
>>>>
>>>> -#define TPM_TIS_IRQ                 5
>>>> +#define TPM_TIS_IRQ                 13
>>
>> Eric,
>>
>>   does this change have any negative side effects on ARM? If you prefer,
>> we can split this part here up into TPM_TIS_ISA_IRQ and TPM_TIS_SYSBUS
>> IRQ and leave the latter at '5' because we know that this is working.
> The IRQ is not advertised in dt nor ACPI on ARM. However it is
> advertised in the capability reg and in the vector. reg So I think this
> should be fixed? I guess on ARM we will pick up a completely different
> IRQ num, allocated from the platform bus slot.


The specification

https://trustedcomputinggroup.org/wp-content/uploads/PC-Client-Specific-Platform-TPM-Profile-for-TPM-2p0-v1p04_r0p37_pub-1.pdf

declares several fields in the Interface Capability Register (table 23, 
pdf page 89) to be mandatory and they must be set to '1'. So I would not 
want to touch those. We can set the interrupt vector register to '0' in 
case interrupts are not supported. Following the spec 0 means that no 
interrupts are supported. I will now split TPM_TIS_IRQ into 
TPM_TIS_ISA_IRQ and TPM_TIS_SYSBUS_IRQ and will in the end set 
TPM_TIS_SYSBUS_IRQ to 'disabled', indicating that IRQs are not 
supported, though they should work even though on ARM there may not be a 
driver to test this with. Does this sound ok?


    Stefan


>
> Thanks
>
> Eric
>>     Stefan
>>
>>
>>>>    #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
>>>>    #define TPM_TIS_LOCALITY_SHIFT      12
>>>> -- 
>>>> 2.24.1
>>>>