Re: [PATCH] hw/misc/aspeed_scu: Handle AST2600 protection key registers correctly

[Tan Siewert <tan@siewert.io>]

On 12.06.25 08:58, Cédric Le Goater wrote:
> LGTM,
> 
> Jamin, Steven, Troy ?
> 

On 12.06.25 01:43, Tan Siewert wrote:
>> -    if (reg > PROT_KEY && !s->regs[PROT_KEY]) {
>> +    if ((reg != AST2600_PROT_KEY && reg != AST2600_PROT_KEY2) && ! 
>> unlocked) {
>>           qemu_log_mask(LOG_GUEST_ERROR, "%s: SCU is locked!\n", 
>> __func__);
>>       }

I just noticed that this never return when the SCU is locked, meaning 
you can still write to the SCU registers even though it is locked. I'll 
send a v2 in a few minutes that addresses this issue too.

The AST2500 SCU handles this correctly here.

Sorry for that!

Cheers,
Tan

>> @@ -738,7 +740,18 @@ static void aspeed_ast2600_scu_write(void 
>> *opaque, hwaddr offset,
>>       switch (reg) {
>>       case AST2600_PROT_KEY:
>> -        s->regs[reg] = (data == ASPEED_SCU_PROT_KEY) ? 1 : 0;
>> +    case AST2600_PROT_KEY2:
>> +        /*
>> +         * Writing a value other than the protection key will lock
>> +         * both protection registers, but unlocking must be done
>> +         * to each protection register individually.
>> +         */
>> +        if (data != ASPEED_SCU_PROT_KEY) {
>> +            s->regs[AST2600_PROT_KEY] = 0;
>> +            s->regs[AST2600_PROT_KEY2] = 0;
>> +        } else {
>> +            s->regs[reg] = (data == ASPEED_SCU_PROT_KEY) ? 1 : 0;
>> +        }
>>           return;
>>       case AST2600_HW_STRAP1:
>>       case AST2600_HW_STRAP2:
>