Re: [PATCH] firmware: smccc: default ARM_SMCCC_SOC_ID to disabled

[Satya Durga Srinivasu Prabhala <satya.prabhala@oss.qualcomm.com>]

Hello Will,

On 1/13/2026 2:57 AM, Will Deacon wrote:
> On Mon, Jan 12, 2026 at 10:24:06PM -0800, Satya Durga Srinivasu Prabhala wrote:
>> The ARM SMCCC SoC ID driver is currently enabled by default and publishes
>> SMCCC-provided SoC identification into /sys/bus/soc/devices/socX/*.
>>
>> On platforms where a vendor SoC driver already exposes widely-consumed
>> attributes (e.g. Qualcomm socinfo [1]), enabling the SMCCC driver changes
>> the format of /sys/devices/soc0/soc_id (e.g. "jep106:XXYY:ZZZZ" instead
>> of a vendor logical ID like "519") and breaks existing userspace consumers.
> Isn't the fundamental issue here that you have multiple callers of
> soc_device_register() and your userspace is only looking at soc0?
Yes, that is right. The issue is we have several products which already
uses the soc0 interface as vendor interface [1] existed even before the
SMCCC SCM ID [2]. Also, per SMCCC specification, SOC ID is an optional
feature. So, vendor specific implementation can take precedence over
standard implementation or a way to disable SMCCC SOC ID could help.

Best,
Satya
>
> Will
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/soc/qcom/socinfo.c?id=efb448d0a3fca01bb987dd70963da6185b81751e
[2]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/firmware/smccc/soc_id.c?id=821b67fa46390baea0ac5139a60eaa48805261b2