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authorMatthias Reichl <hias@horus.com>2018-01-17 13:50:50 +0100
committerMark Brown <broonie@kernel.org>2018-01-18 11:21:17 +0000
commit8d5737a5f53902a916ee1e1cb248c9b8b883b2ea (patch)
tree6190a3acc8c0355222550a611829e8261828614e /sound/soc/bcm
parent4fbd8d194f06c8a3fd2af1ce560ddb31f7ec8323 (diff)
downloadlinux-8d5737a5f53902a916ee1e1cb248c9b8b883b2ea.tar.bz2
ASoC: bcm2835: fix hw_params error when device is in prepared state
If bcm2835 is configured as bitclock master calling hw_params() after prepare() fails with EBUSY. This also makes it impossible to use bcm2835 in full duplex mode. The error is caused by the split clock setup: clk_set_rate is called in hw_params, clk_prepare_enable in prepare. As hw_params doesn't check if the clock was already enabled clk_set_rate fails with EBUSY. Fix this by moving clock startup from prepare to hw_params and let hw_params properly deal with an already set up or enabled clock. Signed-off-by: Matthias Reichl <hias@horus.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/bcm')
-rw-r--r--sound/soc/bcm/bcm2835-i2s.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c
index 2e449d7173fc..d5f73a8ab893 100644
--- a/sound/soc/bcm/bcm2835-i2s.c
+++ b/sound/soc/bcm/bcm2835-i2s.c
@@ -130,6 +130,7 @@ struct bcm2835_i2s_dev {
struct regmap *i2s_regmap;
struct clk *clk;
bool clk_prepared;
+ int clk_rate;
};
static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
@@ -419,10 +420,19 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
}
/* Clock should only be set up here if CPU is clock master */
- if (bit_clock_master) {
- ret = clk_set_rate(dev->clk, bclk_rate);
- if (ret)
- return ret;
+ if (bit_clock_master &&
+ (!dev->clk_prepared || dev->clk_rate != bclk_rate)) {
+ if (dev->clk_prepared)
+ bcm2835_i2s_stop_clock(dev);
+
+ if (dev->clk_rate != bclk_rate) {
+ ret = clk_set_rate(dev->clk, bclk_rate);
+ if (ret)
+ return ret;
+ dev->clk_rate = bclk_rate;
+ }
+
+ bcm2835_i2s_start_clock(dev);
}
/* Setup the frame format */
@@ -618,8 +628,6 @@ static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream,
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
uint32_t cs_reg;
- bcm2835_i2s_start_clock(dev);
-
/*
* Clear both FIFOs if the one that should be started
* is not empty at the moment. This should only happen