Re: [PATCH 4/4] dt-bindings: firmware: Add Qualcomm UEFI Secure Application client

[Maximilian Luz <luzmaximilian@gmail.com>]

On 7/28/22 13:21, Sudeep Holla wrote:
> On Thu, Jul 28, 2022 at 12:05:15PM +0200, Maximilian Luz wrote:
>> On 7/28/22 10:23, Sudeep Holla wrote:
> 
> [...]
> 
>>> Worst case I am fine with that as this needs to be one of and future
>>> platforms must get their act right in designing their f/w interface.
>>
>> Again, I fully agree with you that this situation shouldn't exist. But
>> reality is sadly different.
>>
> 
> As I mentioned I don't have final authority to say yes or no to DT bindings.
> I have expressed my opinion and I thing allowing this to be generic via DT
> bindings gives no incentive to get the firmware story right. Hence I am happy
> to see this as one-off driver change and then we more changes are added to
> the driver or similar drivers get added in the future, we have a change to
> demand what action has been taken to fix the firmware story.
> 
> Just adding DT support(which I disagree) will make future platform to just
> use it and not get improvements in areas of discovery or query from the
> firmware.

Okay, that is a good point. Although it's probably debatable how much
control we have over what goes on with WoA devices.

Would something like this work for you: Add a compatible for the TrEE
interface (e.g. qcom,sc8180x-tee) but not for the specific apps running
in that and then instantiate the app-specific sub-devices from that. We
would still have to hard-code app-names in the driver (i.e. shift the
problem from DT to driver and potentially create soc-specific lists),
but they're no longer in DT (again, I'm not a particular fan of this but
I could live with that, if needed).

We can then look for a solution for apps that need to be manually loaded
or vendor/device specific apps once those becomes an issue.

Regards,
Max