On Fri, 02 Nov 2018 08:30:47 +0100, Jenny TC wrote:
Some DMICs require a delay as defined in the DMIC data sheet to complete DMIC mode transitions. DMIC may enter a bad state if the clock is stopped before successful mode transition. To handle this, a delay is introduced in the STOP STREAM to ensure the clock is running for the mode switch delay duration. A module parameter is introduced to pass the delay as a module parameter.
Signed-off-by: Sathyanarayana Nujella sathyanarayana.nujella@intel.com Signed-off-by: Jairaj Arava jairaj.arava@intel.com Signed-off-by: Harsha Priya harshapriya.n@intel.com
sound/soc/codecs/dmic.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/sound/soc/codecs/dmic.c b/sound/soc/codecs/dmic.c index 8c4926d..0527bc2 100644 --- a/sound/soc/codecs/dmic.c +++ b/sound/soc/codecs/dmic.c @@ -30,9 +30,35 @@ #include <sound/soc.h> #include <sound/soc-dapm.h>
+static int modeswitch_delay_ms; +module_param(modeswitch_delay_ms, uint, 0644);
signed or unsigned?
struct dmic { struct gpio_desc *gpio_en; int wakeup_delay;
- /* Delay after DMIC mode switch */
- int modeswitch_delay_ms;
+};
+int dmic_daiops_trigger(struct snd_pcm_substream *substream,
int cmd, struct snd_soc_dai *dai)+{
- struct snd_soc_component *component = dai->component;
- struct dmic *dmic = snd_soc_component_get_drvdata(component);
- switch (cmd) {
- case SNDRV_PCM_TRIGGER_STOP:
if (dmic->modeswitch_delay_ms)mdelay(dmic->modeswitch_delay_ms);
You need to have a value sanity check either at execution time or at initialization time. The current code allows user to stall for a quite long time by passing some bad value via module option.
thanks,
Takashi