[v3] Support reading Subsystem ID from Device Tree

[PATCH v3 0/2] Support reading Subsystem ID from Device Tree

Posted by Stefan Binding 2 weeks ago

In PC systems using ACPI, the driver is able to read back an SSID from
the _SUB property. This SSID uniquely identifies the system, which
enables the driver to read the correct firmware and tuning for that
system from linux-firmware. Currently there is no way of reading this
property from device tree. Add an equivalent property in device tree
to perform the same role.

Changes since v2:
- Fixed use of PTR_ERR, using PTR_ERR_OR_ZERO instead
- Update commit message of patch 1 to explain why we need SSID property

Changes since v1:
- Fixed device tree property type

Stefan Binding (2):
  ASoC: dt-bindings: cirrus,cs35l41: Document the cirrus,subsystem-id
    property
  ASoC: cs35l41: Fallback to reading Subsystem ID property if not ACPI

 .../bindings/sound/cirrus,cs35l41.yaml        |  6 ++
 sound/soc/codecs/cs35l41.c                    | 77 +++++++++++--------
 2 files changed, 50 insertions(+), 33 deletions(-)

-- 
2.43.0

Re: [PATCH v3 0/2] Support reading Subsystem ID from Device Tree

Posted by Mark Brown 1 week, 1 day ago

On Wed, 17 Sep 2025 16:37:10 +0100, Stefan Binding wrote:
> In PC systems using ACPI, the driver is able to read back an SSID from
> the _SUB property. This SSID uniquely identifies the system, which
> enables the driver to read the correct firmware and tuning for that
> system from linux-firmware. Currently there is no way of reading this
> property from device tree. Add an equivalent property in device tree
> to perform the same role.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/2] ASoC: dt-bindings: cirrus,cs35l41: Document the cirrus,subsystem-id property
      commit: f8673e4069b2032bf9f854bae818a7bdbdca7520
[2/2] ASoC: cs35l41: Fallback to reading Subsystem ID property if not ACPI
      commit: 46c8b4d2a693eca69a2191436cffa44f489e98c7

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark