[alsa-devel] [PATCH 7/7] ASoC: Only write back non-default registers when resuming WM8753

[Mark Brown]

This will reduce the number of writes done on resume, allowing that to
complete faster (especially on systems with very slow I2C like the
current Samsung driver).

Signed-off-by: Mark Brown <broonie at opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm8753.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/sound/soc/codecs/wm8753.c b/sound/soc/codecs/wm8753.c
index bc29558..2241204 100644
--- a/sound/soc/codecs/wm8753.c
+++ b/sound/soc/codecs/wm8753.c
@@ -1526,6 +1526,11 @@ static int wm8753_resume(struct platform_device *pdev)
 	for (i = 0; i < ARRAY_SIZE(wm8753_reg); i++) {
 		if (i + 1 == WM8753_RESET)
 			continue;
+
+		/* No point in writing hardware default values back */
+		if (cache[i] == wm8753_reg[i])
+			continue;
+
 		data[0] = ((i + 1) << 1) | ((cache[i] >> 8) & 0x0001);
 		data[1] = cache[i] & 0x00ff;
 		codec->hw_write(codec->control_data, data, 2);
-- 
1.6.1.3