Re: [PATCH] ALSA: pcm: fix incorrect hw_base increase

Dne 15. 05. 20 v 11:04 Lu, Brent napsal(a):

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Is this a bugfix needed for older kernels as well? When did this issue show up?

thanks,

greg k-h

It happens when DMA stop moving data from host to DSP/DAI for a long time (> half of buffer time). I know host driver should do something about it. But if not, the HWSYNC will keep increasing the hw_base and hw_ptr and confuses user space program.

I'm afraid, but with this code, you turn off the hw_ptr jiffies code. It would be better to fix the driver in this case (return the updated / estimated DMA pointer, increase DMA buffer size etc.). This "lag" is unacceptable.

Jaroslav

Regards, Brent