[alsa-devel] RFC: workaround for 'azx_get_response timeout, switching to polling mode...'

[Maxim Levitsky]

Hi,

Although I thought that polling mode is harmless, it sometimes isn't.
I found out that after few dozens of hibernate cycles, the timeout would
happen again kicking out first MSI, and then whole RRIB (single_cmd).

However, I also found out that if I resend the command that caused the
timeout, it would complete normally.
Even futher, it is possible to poll for this command, and send next
normally. It just works.
So interrupts do work, but sometimes (very rarely) are missed. It might
be even a hardware bug.

The patch I send allows to delay switch to polling till we get 3 such
timeouts in a row.

I tested this approach for about 130 hibernate cycles.

Best regards,
Maxim Levitsky