ASoC: Only write back non-default registers when resuming WM8753

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@opensource.wolfsonmicro.com>

diff --git a/sound/soc/codecs/wm8753.c b/sound/soc/codecs/wm8753.c
index bc29558149e9e9e8e90e3ec55d16b06df9941d86..2241204b5151f70296bb551243080ef710c5fa99 100644 (file)
--- 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);