[PATCH 0/6] ASoC: codecs: Fix resource leaks on card re-bind

[Chancel Liu]

From: Chancel Liu <chancel.liu@xxxxxxx>

Several ASoC codec drivers set up per-device resources from their ASoC
component probe, but the associated cleanup is tied to the underlying bus
(I2C/SPI) device rather than being balanced per component probe. This is
fine for a plain probe/remove, but it breaks when the sound card is
unregistered and re-registered while the bus device stays bound (a card
re-bind): the component probe runs again while the previous bus-level
resources are still live.

Two kinds of resources are affected:

- Regulator disable notifiers (wm8962, wm8995, tlv320aic31xx,
  tlv320aic3x)
  The same notifier_block is re-registered on the
  still-registered regulator notifier chain, which triggers

    notifier callback ..._regulator_event_N already registered
    WARNING: ... at kernel/notifier.c:23 notifier_chain_register

  and corrupts the chain.

- Beep input devices (wm8962, cs42l52, cs42l56)
  A new input device is allocated and registered on every component
  probe while the free path only clears the pointer, leaking the
  previous input device and its sysfs/input node.

The two problems need opposite fixes: the notifiers are registered from
the component probe, so the registration is moved to the bus probe so it
runs once per bus bind; the beep device is freed from the component
remove path, so it is switched from devm_input_allocate_device() to
input_allocate_device() paired with an explicit
input_unregister_device() on that same free path.

Verified with wm8962. The remaining patches fix other codec drivers
following the same patterns.

Chancel Liu (6):
  ASoC: wm8962: Fix regulator notifier and beep leaks on card re-bind
  ASoC: wm8995: Register regulator notifiers from the bus probe
  ASoC: tlv320aic31xx: Register regulator notifier from the I2C probe
  ASoC: tlv320aic3x: Register regulator notifier from the bus probe
  ASoC: cs42l52: Fix beep input device leak on card re-bind
  ASoC: cs42l56: Fix beep input device leak on card re-bind

 sound/soc/codecs/cs42l52.c       |  9 ++++--
 sound/soc/codecs/cs42l56.c       |  9 ++++--
 sound/soc/codecs/tlv320aic31xx.c | 30 +++++++++---------
 sound/soc/codecs/tlv320aic3x.c   | 28 ++++++++---------
 sound/soc/codecs/wm8962.c        | 52 +++++++++++++++++---------------
 sound/soc/codecs/wm8995.c        | 41 ++++++++++++++++---------
 6 files changed, 96 insertions(+), 73 deletions(-)

--
2.50.1