From 0f72a8a39cd033a26bddafe2b101d12cac039bdc Mon Sep 17 00:00:00 2001 From: Charles Keepax Date: Fri, 2 Sep 2016 16:52:45 +0100 Subject: [PATCH] ASoC: arizona: Avoid changing SYNC_ENA whilst the FLL_ENA is set For best performance changing the synchroniser state whilst the FLL is running should be avoided. As this has been done fairly regularly in practice rather than hard preventing this, simply improve the FLL enable sequence and give a warning if the user changes the synchroniser state. Signed-off-by: Charles Keepax Signed-off-by: Mark Brown --- sound/soc/codecs/arizona.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c index 5455d0e..fae6ccf 100644 --- a/sound/soc/codecs/arizona.c +++ b/sound/soc/codecs/arizona.c @@ -2209,12 +2209,15 @@ static int arizona_enable_fll(struct arizona_fll *fll) struct arizona *arizona = fll->arizona; bool use_sync = false; int already_enabled = arizona_is_enabled_fll(fll, fll->base); + int sync_enabled = arizona_is_enabled_fll(fll, fll->base + 0x10); struct arizona_fll_cfg cfg; int i; unsigned int val; if (already_enabled < 0) return already_enabled; + if (sync_enabled < 0) + return sync_enabled; if (already_enabled) { /* Facilitate smooth refclk across the transition */ @@ -2255,6 +2258,9 @@ static int arizona_enable_fll(struct arizona_fll *fll) return -EINVAL; } + if (already_enabled && !!sync_enabled != use_sync) + arizona_fll_warn(fll, "Synchroniser changed on active FLL\n"); + /* * Increase the bandwidth if we're not using a low frequency * sync source. @@ -2270,12 +2276,12 @@ static int arizona_enable_fll(struct arizona_fll *fll) if (!already_enabled) pm_runtime_get(arizona->dev); - regmap_update_bits_async(arizona->regmap, fll->base + 1, - ARIZONA_FLL1_ENA, ARIZONA_FLL1_ENA); if (use_sync) regmap_update_bits_async(arizona->regmap, fll->base + 0x11, ARIZONA_FLL1_SYNC_ENA, ARIZONA_FLL1_SYNC_ENA); + regmap_update_bits_async(arizona->regmap, fll->base + 1, + ARIZONA_FLL1_ENA, ARIZONA_FLL1_ENA); if (already_enabled) regmap_update_bits_async(arizona->regmap, fll->base + 1, -- 2.7.4