diff options
| author | Matthias Reichl <hias@horus.com> | 2018-01-17 13:50:50 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-01-18 12:21:17 +0100 |
| commit | 8d5737a5f53902a916ee1e1cb248c9b8b883b2ea (patch) | |
| tree | 6190a3acc8c0355222550a611829e8261828614e /sound | |
| parent | Linux 4.15-rc1 (diff) | |
| download | linux-8d5737a5f53902a916ee1e1cb248c9b8b883b2ea.tar.xz linux-8d5737a5f53902a916ee1e1cb248c9b8b883b2ea.zip | |
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')
| -rw-r--r-- | sound/soc/bcm/bcm2835-i2s.c | 20 |
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 |