Re: [PATCH] ALSA: hda/tas2781: do not use regcache

From: Takashi Iwai
Date: Fri Dec 29 2023 - 07:45:57 EST


On Fri, 22 Dec 2023 00:48:56 +0100,
Gergo Koteles wrote:
>
> There are two problems with using regcache in this module.
>
> The amplifier has 3 addressing levels (BOOK, PAGE, REG). The firmware
> contains blocks that must be written to BOOK 0x8C. The regcache doesn't
> know anything about BOOK, so regcache_sync writes invalid values to the
> actual BOOK.
>
> The module handles 2 or more separate amplifiers. The amplifiers have
> different register values, and the module uses only one regmap/regcache
> for all the amplifiers. The regcache_sync only writes the last amplifier
> used.
>
> The module successfully restores all the written register values (RC
> profile, program, configuration, calibration) without regcache.
>
> Remove regcache functions and set regmap cache_type to REGCACHE_NONE.
>
> Link: https://lore.kernel.org/r/21a183b5a08cb23b193af78d4b1114cc59419272.1701906455.git.soyer@xxxxxx/
>
> Fixes: 5be27f1e3ec9 ("ALSA: hda/tas2781: Add tas2781 HDA driver")
> CC: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Gergo Koteles <soyer@xxxxxx>

Applied to for-linus branch now. Thanks.


Takashi