Hi,
we have AM3703 based board similar to BeagleBoard. I'm hitting this error after upgrade to latest LTS 4.19.71 (upgraded from 4.1):
omap-mcbsp 49022000.mcbsp: TX Buffer Overflow!
This appears during or after playing of short (~2s) ding-dong wav. That error exists for longer time, because handling of tx buffer overflow irq was introduced in 2016: 4e85e7776eba ("ASoC: omap-mcbsp: Enable TX/RX under and overflow interrupts"). I've cherry-picked it to 4.1 and I see the error there also. The sound seems clear and ok to me, but we are using low quality speaker.
There are two workarounds to get rid of the message: 1) Change 'dma_op_mode' sysfs attribute from 'element' to 'threshold'. I found that just by coincidence when checking sysfs attributes. 2) Compile kernel with CONFIG_VIDEO_OMAP3=y. Found on Logic PD forum [1].
Does anybody have any idea what's going wrong? Or why these (somehow) unrelated workarounds help?
Thanks,
Tomas
[1] https://support.logicpd.com/TDGForum/tabid/124/aft/2277/Default.aspx