linux/sound/soc/sh/rcar
Kuninori Morimoto a122a116fc
ASoC: rsnd: call rsnd_ssi_master_clk_start() from rsnd_ssi_init()
Current rsnd needs to call .prepare (P) for clock settings,
.trigger for playback start (S) and stop (E).
It should be called as below from SSI point of view.

	P -> S -> E -> P -> S -> E -> ...

But, if you used MIXer, below case might happen

	              (2)
	1: P -> S ---> E -> ...
	2:         P ----> S -> ...
	          (1)     (3)

P(1) setups clock, but E(2) resets it. and starts playback (3).
In such case, it will reports "SSI parent/child should use same rate".

rsnd_ssi_master_clk_start() which is the main function at (P)
was called from rsnd_ssi_init() (= S) before,
but was moved by below patch to rsnd_soc_dai_prepare() (= P) to avoid
using clk_get_rate() which shouldn't be used under atomic context.

	commit 4d230d1271 ("ASoC: rsnd: fixup not to call clk_get/set
				under non-atomic")

Because of above patch, rsnd_ssi_master_clk_start() is now called at (P)
which is for non atomic context. But (P) is assuming that spin lock is
*not* used.
One issue now is rsnd_ssi_master_clk_start() is checking ssi->xxx
which should be protected by spin lock.

After above patch, adg.c had below patch for other reasons.

	commit 06e8f5c842 ("ASoC: rsnd: don't call clk_get_rate()
				under atomic context")

clk_get_rate() is used at probe() timing by this patch.
In other words, rsnd_ssi_master_clk_start() is no longer using
clk_get_rate() any more.

This means we can call it from rsnd_ssi_init() (= S) again which is
protected by spin lock.
This patch re-move it to under spin lock, and solves
1. checking ssi->xxx without spin lock issue.
2. clk setting / device start / device stop race condition.

Reported-by: Linh Phung T. Y. <linh.phung.jy@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/875z0x1jt5.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-14 15:24:09 +01:00
..
adg.c ASoC: rsnd: cleanup ppcheck warning for adg.c 2021-03-10 13:07:13 +00:00
cmd.c ASoC: rsnd: cleanup ppcheck warning for cmd.c 2021-03-10 13:07:12 +00:00
core.c ASoC: rsnd: core: Check convert rate in rsnd_hw_params 2021-03-16 13:29:37 +00:00
ctu.c ASoC: sh: rcar: ctu: add missing error check 2021-03-10 13:07:02 +00:00
dma.c Merge branch 'for-5.4' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into asoc-5.5 2019-11-06 16:29:34 +00:00
dvc.c Merge branch 'for-4.20' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into asoc-4.21 intel dep 2018-12-13 14:36:46 +00:00
gen.c SoC: rsnd: add interrupt support for SSI BUSIF buffer 2020-05-12 10:56:21 +01:00
Makefile ASoC: rsnd: convert to SPDX identifiers 2018-06-18 12:16:46 +01:00
mix.c ASoC: rsnd: move .get_status under rsnd_mod_ops 2018-11-05 11:27:29 +00:00
rsnd.h ASoC: sh: rcar: align function prototypes 2021-03-10 13:07:00 +00:00
src.c ASoC: rsnd: src: fix compiler warnings 2019-03-11 16:59:04 +00:00
ssi.c ASoC: rsnd: call rsnd_ssi_master_clk_start() from rsnd_ssi_init() 2021-04-14 15:24:09 +01:00
ssiu.c ASoC: rsnd: cleanup ppcheck warning for ssiu.c 2021-03-10 13:07:09 +00:00