[alsa-devel] [PATCH] ASoC: soc-core: Add support for NULL default register caches

Timur Tabi timur at freescale.com
Mon Jan 10 23:10:52 CET 2011

Dimitris Papastamos wrote:
> The infrastructure for handling NULL default register maps is already
> included in the soc-cache code, just ensure that we don't try to dereference
> a NULL pointer while accessing a NULL register cache.
> Signed-off-by: Dimitris Papastamos <dp at opensource.wolfsonmicro.com>

Acked-by: Timur Tabi <timur at freescale.com>

This fixes the kernel panic I was seeing earlier with my CS4270 driver, but it's
not a replacement for my patch, "[v3] ASoC: cs4270: use the built-in register
cache support".

With Dimitris' patch alone, the CS4270 still has other bugs:

# cat ./devices/platform/soc-audio/playback/codec_reg
cs4270-codec.0-004f registers
 0: <no data: -5>
 1:   c3
 2:    0
 3:   30
 4:    0
 5:    0
 6:    0
 7:    0

So both patches need to be applied, however, I can't say whether Dimitris' patch
is sufficient for handling NULL default register maps, since I removed that from
my driver.

Timur Tabi
Linux kernel developer at Freescale

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