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c66234cfed
When restoring registers during runtime resume, we must not write to
I2S_TXDR which is the transmit FIFO as this queues up a sample to be
output and pushes all of the output channels down by one.
This can be demonstrated with the speaker-test utility:
for i in a b c; do speaker-test -c 2 -s 1; done
which should play a test through the left speaker three times but if the
I2S hardware starts runtime suspended the first sample will be played
through the right speaker.
Fix this by marking I2S_TXDR as volatile (which also requires marking it
as readble, even though it technically isn't). This seems to be the
most robust fix, the alternative of giving I2S_TXDR a default value is
more fragile since it does not prevent regcache writing to the register
in all circumstances.
While here, also fix the configuration of I2S_RXDR and I2S_FIFOLR; these
are not writable so they do not suffer from the same problem as I2S_TXDR
but reading from I2S_RXDR does suffer from a similar problem.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| rk3288_hdmi_analog.c | ||
| rk3399_gru_sound.c | ||
| rockchip_i2s.c | ||
| rockchip_i2s.h | ||
| rockchip_max98090.c | ||
| rockchip_pdm.c | ||
| rockchip_pdm.h | ||
| rockchip_rt5645.c | ||
| rockchip_spdif.c | ||
| rockchip_spdif.h | ||