On Thu, Sep 28, 2023 at 11:49:25AM +0800, lihuisong (C) wrote: > > 在 2023/9/27 21:59, Sudeep Holla 写道: > > On Wed, Sep 27, 2023 at 10:07:15AM +0800, lihuisong (C) wrote: [...] > > > > +/* Generic Communications Channel Shared Memory Region */ > > > > +#define PCC_SIGNATURE 0x50424300 > > > Why is this signature 0x50424300? > > It is as per the specification. > > > > > In ACPI spec, this signature is all 0x50434303. > > No, not exactly. It is just an example. > > The PCC signature - The signature of a subspace is computed by a bitwise-or > > of the value 0x50434300 with the subspace ID. For example, subspace 3 has > > signature 0x50434303 > Sorry for my mistake. I know this. > I mean, why doesn't the following macro follow spec and define this > signature as 0x504*3*430. > "#define PCC_SIGNATURE **0x504*2*4300*"* > Because it seems that all version of ACPI spec is 0x5043430. Sorry my mistake. Stupidly the existing drivers have it wrong and I just copied them without paying much attention. I will fix it up. It must be 0x50434300 instead of 0x50424300. If you have no other comments, can you please ack v2 patch 4/4 changing soc kunpeng_hccs driver. I will fixup the PCC_SIGNATURE and send it as part of my PR to Rafael. Refer [1] for the change in PCC_SIGNATURE, sorry for missing the point. I was confident that the existing code is correct :), but I am wrong. -- Regards, Sudeep [1] https://git.kernel.org/sudeep.holla/l/pcc_defines
