Re: [PATCH] soc: qcom: Add SoC info driver

From: Imran Khan
Date: Thu Oct 27 2016 - 09:50:08 EST


On 10/26/2016 8:16 PM, Arnd Bergmann wrote:
> On Wednesday, October 26, 2016 7:42:08 PM CEST Imran Khan wrote:
>> On 10/26/2016 7:35 PM, Arnd Bergmann wrote:
>>>>> As we are talking about generic soc_device_attribute fields, I was hoping that
>>>>> having a vendor field would be helpful as along with family it would provide
>>>>> a more thorough information. Also as more than one foundries may be used for
>>>>> a soc, can we have a field say foundry_id to provide this information.
>>> My first feeling is that this 'vendor' information can should be
>>> derived from the family. It's also not clear what would happen
>>> to this when a company gets bought. E.g. the Oxnas product family
>>> was subsequently owned by Oxford, PLX, Avago and Broadcom, and the
>>> mxs family was Sigmatel, Freescale, now NXP and might soon be
>>> Qualcomm. What would you put in there in this case?
>>
>> Okay, not having vendor field is fine for me. Could you also suggest
>> something about the foundry_id field.
>
> This one seems more well-defined, so it's probably ok to add. What
> would be the use case of reading this? Would you want to read it
> just from user space or also from the kernel?
>

As of now the use case I can think of, only involve reading this from user
space. For example for the same soc, coming from different foundries with
different manufacturing process, we may have a situation where some inconsistent
h/w behavior is being observed only on parts received from a certain foundry
and in those cases this information may help in segregation of problematic socs
and may also be used in testing these socs under a different set of settings like
voltage, frequency etc.

> Maybe this can be combined with a manufacturing process, which probably
> falls into a similar category, so we could have something like
> "TSMC 28ULP" as a string in there.
>

Yes. Having a manufacturing process as part of foundry-id can provide a more
thorough information.

> Arnd
>


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