This series is a result of long-running debugging of rarely screwed I2S stream out of EP9302 chip. Logic analyser shows that the stream is shifted by one byte (out of 32 bits per sample) which leads to noise intead of original stream.
DMA is verified to work fine (no underrun). The issue is only reproducible under high load (CPU or AMBA bus -- not yet clear). This stream corruption happens at the same time I2S controller reports internal FIFO underrun (even though according to documentation, it should handle an underrun gracefully).
First two patches are fixing unrelated issues in I2S driver found during debugging of the stream shift. Third one is simplification of the driver to prepare for workaround.
Both controller configuration options for TX FIFO underrun handling were tested, both do not work reliable. Hence, this ugly watchdog in the last patch.
The whole series is tested on a board similar to EDB9302 (identical in sound part).
Alexander Sverdlin (5): ASoC: cirrus: i2s: Fix LRCLK configuration ASoC: cirrus: i2s: Fix {TX|RX}LinCtrlData setup ASoC: cirrus: i2s: Stop enabling I2S2 and I2S3 FIFOs ARM: ep93xx: i2s: Add IRQ to platform device resources ASoC: cirrus: i2s: IRQ-based stream watchdog
arch/arm/mach-ep93xx/core.c | 1 + sound/soc/cirrus/Kconfig | 17 +++++++ sound/soc/cirrus/edb93xx.c | 2 +- sound/soc/cirrus/ep93xx-i2s.c | 106 +++++++++++++++++++++++++++++++++-------- sound/soc/cirrus/snappercl15.c | 2 +- 5 files changed, 106 insertions(+), 22 deletions(-)