4 Feb
2010
4 Feb
'10
9:20 p.m.
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