soundwire: honor clock_reg_supported in the clock scaling check

Browse source

sdw_slave_set_frequency() treats class_id and prop.clock_reg_supported
as equivalent evidence that a slave implements the bus-clock base and
scale registers, but the bank-switch reprogramming path checks class_id
alone, so a class-0 slave that declared the registers never gets the
next-bank scale written there. The registers are SoundWire 1.2, not
SDCA, so a device may well implement them without setting the class
field.

Extend the helper to honor clock_reg_supported, as discussed with
Pierre-Louis in the WCD9378 review. This also makes a link whose
peripherals all declare clock_reg_supported eligible for dynamic clock
scaling in the generic bandwidth allocation, which is what declaring
the registers means.

With the helper extended, sdw_slave_set_frequency()'s open-coded test
computes the same predicate; call the helper there instead, so future
quirks or updates land in one place.

Link: https://lore.kernel.org/all/5717102b-f7ab-42b2-8065-064d94dd2bee@linux.dev/
Link: https://lore.kernel.org/all/6991398d-4ae4-45ee-85d0-3b66462fec1d@linux.dev/
Assisted-by: Claude:claude-fable-5
Signed-off-by: Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20260728173542.61146-2-jorijnvdgraaf@catcrafts.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>

...

This commit is contained in:

Jorijn van der Graaf 2026-07-28 19:35:42 +02:00 • committed by Vinod Koul

parent f64c5d5ff8

commit b3d2703946

1 changed files with 5 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

7

drivers/soundwire/bus.c

View file