From: Jiada Wang jiada_wang@mentor.com
Clocking operations clk_get/set_rate, are non-atomic, they shouldn't be called in soc_pcm_trigger() which is atomic.
Following issue was found due to execution of clk_get_rate() causes sleep in soc_pcm_trigger(), which shouldn't be blocked.
We can reproduce this issue by following > enable CONFIG_DEBUG_ATOMIC_SLEEP=y > compile, and boot > mount -t debugfs none /sys/kernel/debug > while true; do cat /sys/kernel/debug/clk/clk_summary > /dev/null; done & > while true; do aplay xxx; done
This patch adds support to .prepare callback, and moves non-atomic clocking operations to it. As .prepare is non-atomic, it is always called before trigger_start/trigger_stop.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 in_atomic(): 1, irqs_disabled(): 128, pid: 2242, name: aplay INFO: lockdep is turned off. irq event stamp: 5964 hardirqs last enabled at (5963): [<ffff200008e59e40>] mutex_lock_nested+0x6e8/0x6f0 hardirqs last disabled at (5964): [<ffff200008e623f0>] _raw_spin_lock_irqsave+0x24/0x68 softirqs last enabled at (5502): [<ffff200008081838>] __do_softirq+0x560/0x10c0 softirqs last disabled at (5495): [<ffff2000080c2e78>] irq_exit+0x160/0x25c Preemption disabled at:[ 62.904063] [<ffff200008be4d48>] snd_pcm_stream_lock+0xb4/0xc0 CPU: 2 PID: 2242 Comm: aplay Tainted: G B C 4.9.54+ #186 Hardware name: Renesas Salvator-X board based on r8a7795 (DT) Call trace: [<ffff20000808fe48>] dump_backtrace+0x0/0x37c [<ffff2000080901d8>] show_stack+0x14/0x1c [<ffff2000086f4458>] dump_stack+0xfc/0x154 [<ffff2000081134a0>] ___might_sleep+0x57c/0x58c [<ffff2000081136b8>] __might_sleep+0x208/0x21c [<ffff200008e5980c>] mutex_lock_nested+0xb4/0x6f0 [<ffff2000087cac74>] clk_prepare_lock+0xb0/0x184 [<ffff2000087cb094>] clk_core_get_rate+0x14/0x54 [<ffff2000087cb0f4>] clk_get_rate+0x20/0x34 [<ffff20000113aa00>] rsnd_adg_ssi_clk_try_start+0x158/0x4f8 [snd_soc_rcar] [<ffff20000113da00>] rsnd_ssi_init+0x668/0x7a0 [snd_soc_rcar] [<ffff200001133ff4>] rsnd_soc_dai_trigger+0x4bc/0xcf8 [snd_soc_rcar] [<ffff200008c1af24>] soc_pcm_trigger+0x2a4/0x2d4
Fixes: e7d850dd10f4 ("ASoC: rsnd: use mod base common method on SSI-parent") Signed-off-by: Jiada Wang jiada_wang@mentor.com Signed-off-by: Timo Wischer twischer@de.adit-jv.com [Kuninori: tidyup for upstream] Signed-off-by: Kuninori Morimoto kuninori.morimoto.gx@renesas.com Tested-by: Hiroyuki Yokoyama hiroyuki.yokoyama.vx@renesas.com --- sound/soc/sh/rcar/core.c | 11 +++++++++++ sound/soc/sh/rcar/rsnd.h | 7 +++++++ sound/soc/sh/rcar/ssi.c | 16 ++++++++++------ 3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c index c66b3da..299fb45 100644 --- a/sound/soc/sh/rcar/core.c +++ b/sound/soc/sh/rcar/core.c @@ -955,12 +955,23 @@ static void rsnd_soc_dai_shutdown(struct snd_pcm_substream *substream, rsnd_dai_stream_quit(io); }
+static int rsnd_soc_dai_prepare(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct rsnd_priv *priv = rsnd_dai_to_priv(dai); + struct rsnd_dai *rdai = rsnd_dai_to_rdai(dai); + struct rsnd_dai_stream *io = rsnd_rdai_to_io(rdai, substream); + + return rsnd_dai_call(prepare, io, priv); +} + static const struct snd_soc_dai_ops rsnd_soc_dai_ops = { .startup = rsnd_soc_dai_startup, .shutdown = rsnd_soc_dai_shutdown, .trigger = rsnd_soc_dai_trigger, .set_fmt = rsnd_soc_dai_set_fmt, .set_tdm_slot = rsnd_soc_set_dai_tdm_slot, + .prepare = rsnd_soc_dai_prepare, };
void rsnd_parse_connect_common(struct rsnd_dai *rdai, diff --git a/sound/soc/sh/rcar/rsnd.h b/sound/soc/sh/rcar/rsnd.h index 7ff58b0..7a04b19 100644 --- a/sound/soc/sh/rcar/rsnd.h +++ b/sound/soc/sh/rcar/rsnd.h @@ -301,6 +301,9 @@ struct rsnd_mod_ops { int (*nolock_stop)(struct rsnd_mod *mod, struct rsnd_dai_stream *io, struct rsnd_priv *priv); + int (*prepare)(struct rsnd_mod *mod, + struct rsnd_dai_stream *io, + struct rsnd_priv *priv); };
struct rsnd_dai_stream; @@ -330,6 +333,7 @@ struct rsnd_mod { * H 0: fallback * H 0: hw_params * H 0: pointer + * H 0: prepare */ #define __rsnd_mod_shift_nolock_start 0 #define __rsnd_mod_shift_nolock_stop 0 @@ -344,6 +348,7 @@ struct rsnd_mod { #define __rsnd_mod_shift_fallback 28 /* always called */ #define __rsnd_mod_shift_hw_params 28 /* always called */ #define __rsnd_mod_shift_pointer 28 /* always called */ +#define __rsnd_mod_shift_prepare 28 /* always called */
#define __rsnd_mod_add_probe 0 #define __rsnd_mod_add_remove 0 @@ -358,6 +363,7 @@ struct rsnd_mod { #define __rsnd_mod_add_fallback 0 #define __rsnd_mod_add_hw_params 0 #define __rsnd_mod_add_pointer 0 +#define __rsnd_mod_add_prepare 0
#define __rsnd_mod_call_probe 0 #define __rsnd_mod_call_remove 0 @@ -372,6 +378,7 @@ struct rsnd_mod { #define __rsnd_mod_call_pointer 0 #define __rsnd_mod_call_nolock_start 0 #define __rsnd_mod_call_nolock_stop 1 +#define __rsnd_mod_call_prepare 0
#define rsnd_mod_to_priv(mod) ((mod)->priv) #define rsnd_mod_name(mod) ((mod)->ops->name) diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c index 85da4fc..3adcc4f 100644 --- a/sound/soc/sh/rcar/ssi.c +++ b/sound/soc/sh/rcar/ssi.c @@ -306,7 +306,7 @@ static int rsnd_ssi_master_clk_start(struct rsnd_mod *mod, if (rsnd_ssi_is_multi_slave(mod, io)) return 0;
- if (ssi->usrcnt > 1) { + if (ssi->rate) { if (ssi->rate != rate) { dev_err(dev, "SSI parent/child should use same rate\n"); return -EINVAL; @@ -464,7 +464,6 @@ static int rsnd_ssi_init(struct rsnd_mod *mod, struct rsnd_priv *priv) { struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod); - int ret;
if (!rsnd_ssi_is_run_mods(mod, io)) return 0; @@ -473,10 +472,6 @@ static int rsnd_ssi_init(struct rsnd_mod *mod,
rsnd_mod_power_on(mod);
- ret = rsnd_ssi_master_clk_start(mod, io); - if (ret < 0) - return ret; - rsnd_ssi_config_init(mod, io);
rsnd_ssi_register_setup(mod); @@ -872,6 +867,13 @@ static int rsnd_ssi_pio_pointer(struct rsnd_mod *mod, return 0; }
+static int rsnd_ssi_prepare(struct rsnd_mod *mod, + struct rsnd_dai_stream *io, + struct rsnd_priv *priv) +{ + return rsnd_ssi_master_clk_start(mod, io); +} + static struct rsnd_mod_ops rsnd_ssi_pio_ops = { .name = SSI_NAME, .probe = rsnd_ssi_common_probe, @@ -884,6 +886,7 @@ static struct rsnd_mod_ops rsnd_ssi_pio_ops = { .pointer = rsnd_ssi_pio_pointer, .pcm_new = rsnd_ssi_pcm_new, .hw_params = rsnd_ssi_hw_params, + .prepare = rsnd_ssi_prepare, };
static int rsnd_ssi_dma_probe(struct rsnd_mod *mod, @@ -959,6 +962,7 @@ static struct rsnd_mod_ops rsnd_ssi_dma_ops = { .pcm_new = rsnd_ssi_pcm_new, .fallback = rsnd_ssi_fallback, .hw_params = rsnd_ssi_hw_params, + .prepare = rsnd_ssi_prepare, };
int rsnd_ssi_is_dma_mode(struct rsnd_mod *mod)