[PATCH v2 7/7] ASoC: apple: mca: Add delay after configuring clock
James Calligeros <[email protected]>
| Newsgroups | dev.linux.lists.asahi,org.kernel.vger.linux-kernel,org.kernel.vger.linux-sound |
|---|---|
| Message-ID | <[email protected]> |
From: Hector Martin <[email protected]> Right after the early FE setup, ADMAC gets told to start the DMA. This can end up in a weird "slip" state with the channels transposed. Waiting a bit fixes this; presumably this allows the clock to stabilize. Signed-off-by: Hector Martin <[email protected]> Signed-off-by: James Calligeros <[email protected]> --- sound/soc/apple/mca.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c index a1da01b0be32..eaa4e81f9a3b 100644 --- a/sound/soc/apple/mca.c +++ b/sound/soc/apple/mca.c @@ -225,6 +225,12 @@ static void mca_fe_early_trigger(struct snd_pcm_substream *substream, int cmd, FIELD_PREP(SERDES_CONF_SYNC_SEL, 0)); mca_modify(cl, serdes_conf, SERDES_CONF_SYNC_SEL, FIELD_PREP(SERDES_CONF_SYNC_SEL, cl->no + 1)); + /* + * ADMAC gets started right after this. This delay seems + * to be needed for that to be reliable, e.g. ensure the + * clock is stable? + */ + udelay(100); break; default: break; -- 2.54.0