Re: [PATCH v2 0/2] Add SoundWire detach helper
From: Pierre-Louis Bossart
Date: Fri Sep 04 2026 - 04:39:33 EST
On 8/31/26 16:01, Charles Keepax wrote:
> Currently, if a SoundWire driver takes an action that causes the device
> to detach from the bus it needs to be careful. There will be a period of
> time until the detach is recognised by the core, if the driver
> immediately
> calls sdw_slave_wait_for_init() it is possible for that to complete
> before the detach has been recognised. Leaving the driver with a device
> that is potentially not ready for what follows.
>
> To avoid this race add a new helper that drivers can use to inform the
> core the device will detach. This clears the enumeration completions
> ensuring that sdw_slave_wait_for_init() can't complete until the device
> re-attaches.
>
> This is the third part of a longer series of moving these slave
> attach/deatach operations into the core:
>
> https://lore.kernel.org/linux-sound/20260512103022.1154645-1-ckeepax@xxxxxxxxxxxxxxxxxxxxx/
> https://lore.kernel.org/linux-sound/20260608102714.2503120-1-ckeepax@xxxxxxxxxxxxxxxxxxxxx/
>
> I have based this series off Vinod's soundwire tree as that probably
> makes sense for which tree to take it through.
>
> Thanks,
> Charles
>
> Changes since v1:
> - Correct kerneldoc
>
> Charles Keepax (2):
> soundwire: Add a helper function to indicate a device will detach
> mfd: cs42l43: Move to core detach helper
>
> drivers/mfd/cs42l43-sdw.c | 2 --
> drivers/mfd/cs42l43.c | 15 +--------------
> drivers/soundwire/bus.h | 6 ------
> include/linux/mfd/cs42l43.h | 1 -
> include/linux/soundwire/sdw.h | 26 ++++++++++++++++++++++++++
> 5 files changed, 27 insertions(+), 23 deletions(-)
LGTM, for the series
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxx>