30 Sep
2015
30 Sep
'15
8:22 p.m.
On Tue, Sep 29, 2015 at 10:43:17PM +0800, yitian wrote:
Designware I2S uses tx empty and rx available signals as the DMA handshaking signals. during music playing, if XRUN occurs, i2s_stop() function will be executed and both tx and rx irq are masked, when music continues to be played, i2s_start() is executed but both tx and rx irq are not unmasked which cause I2S stop sending DMA handshaking signal to DMA controller, and it finally causes music playing will be stopped once XRUN occurs for the first time.
I'm a bit concerned about how this code ever worked given the above description - is there some race condition which allows things to work if we're lucky?