[PATCH 0/5] ASoC: TI codecs: sort the reg_defaults tables

[Peter Ujfalusi <peter.ujfalusi@linux.intel.com>]

The reg_defaults array of a regmap_config must be sorted by ascending
register address: regcache_lookup_reg() finds entries in it with
bsearch(), and regcache_init() only kmemdup_array()s the array, it never
sorts it.  See commit fd80df352ba1 ("regcache: Add support for sorting
defaults arrays").

When the array is not sorted, bsearch() descends into the wrong half and
a number of entries can never be found.  regcache_reg_needs_sync() then
cannot compare the cached value against the default and always reports
that a sync is needed, so those registers are written to the device on
every regcache_sync() even if they were never touched.

I found this while chasing a SoundWire NAK on an unimplemented register
and audited the reg_defaults tables in sound/ by replaying lib/bsearch.c
over each of them.  These are the affected TI/Burr-Brown codecs:

  pcm512x_reg_defaults    45 entries, 24 unreachable
  tas675x_reg_defaults    69 entries, 14 unreachable
  tas2552_reg_defs        21 entries,  7 unreachable
  tas2764_reg_defaults    11 entries,  1 unreachable
  tas2780_reg_defaults    10 entries,  1 unreachable

The patches only reorder the existing entries.  The text of every entry
is kept verbatim, no default value is changed, and each resulting table
was verified to be fully reachable.

tas2783-sdw was fixed separately, it had already been posted.

The series is based on broonie/for-linus.

Peter Ujfalusi (5):
  ASoC: pcm512x: sort the register default table
  ASoC: tas2552: sort the register default table
  ASoC: tas2764: sort the register default table
  ASoC: tas2780: sort the register default table
  ASoC: tas675x: sort the register default table

 sound/soc/codecs/pcm512x.c | 40 +++++++++++++++++++-------------------
 sound/soc/codecs/tas2552.c | 14 ++++++-------
 sound/soc/codecs/tas2764.c |  2 +-
 sound/soc/codecs/tas2780.c |  2 +-
 sound/soc/codecs/tas675x.c | 18 ++++++++---------
 5 files changed, 38 insertions(+), 38 deletions(-)

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2.55.0