From: Viorel Suman <viorel.suman@xxxxxxx>
On BIAS STANDBY->OFF transition the current implementation sleeps
600ms on suspend in order to discharge the chip. The suspend is
propagated from "snd_soc_suspend" call for all audio cards in a
serial fashion, thus in case of boards like i.MX8DXL EVK which has
3 distinct WM8960 codecs the total cumulated sleep on suspend is 1.8
seconds.
On the other hand the BIAS OFF->STANDBY transition happens
asynchronously with regard to "snd_soc_resume" - the call is
propagated from "soc_resume_deferred" which is just scheduled
from "snd_soc_resume", each card having its own work scheduled to
execute "soc_resume_deferred" call.
The patch performs discharge completion on BIAS OFF->STANDBY transition
so that the cumulated effect on suspend described above is avoided
and discharge is completed in paralel in case of multiple WM8960
codecs on the board.
Signed-off-by: Viorel Suman <viorel.suman@xxxxxxx>
---
sound/soc/codecs/wm8960.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 75de6a81465df..b7a2246184e08 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -45,6 +45,8 @@
#define WM8960_DISOP 0x40
#define WM8960_DRES_MASK 0x30
+#define WM8960_DSCH_TOUT 600 /* discharge timeout, ms */
+
static bool is_pll_freq_available(unsigned int source, unsigned int target);
static int wm8960_set_pll(struct snd_soc_component *component,
unsigned int freq_in, unsigned int freq_out);
@@ -133,6 +135,7 @@ struct wm8960_priv {
int freq_in;
bool is_stream_in_use[2];
struct wm8960_data pdata;
+ ktime_t dsch_start;
};
#define wm8960_reset(c) regmap_write(c, WM8960_RESET, 0)
@@ -898,6 +901,7 @@ static int wm8960_set_bias_level_out3(struct snd_soc_component *component,
struct wm8960_priv *wm8960 = snd_soc_component_get_drvdata(component);
u16 pm2 = snd_soc_component_read(component, WM8960_POWER2);
int ret;
+ ktime_t tout;
switch (level) {
case SND_SOC_BIAS_ON:
@@ -944,6 +948,11 @@ static int wm8960_set_bias_level_out3(struct snd_soc_component *component,
case SND_SOC_BIAS_STANDBY:
if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_OFF) {
+ /* ensure discharge is complete */
+ tout = WM8960_DSCH_TOUT - ktime_ms_delta(ktime_get(), wm8960->dsch_start);
+ if (tout > 0)
+ msleep(tout);
+
regcache_sync(wm8960->regmap);
/* Enable anti-pop features */
@@ -973,9 +982,9 @@ static int wm8960_set_bias_level_out3(struct snd_soc_component *component,
WM8960_POBCTRL | WM8960_SOFT_ST |
WM8960_BUFDCOPEN | WM8960_BUFIOEN);
- /* Disable VMID and VREF, let them discharge */
+ /* Disable VMID and VREF, mark discharge */
snd_soc_component_write(component, WM8960_POWER1, 0);
- msleep(600);
+ wm8960->dsch_start = ktime_get();
break;
}
--
2.26.3
