RE: sata_mv port lockup on hotplug (kernel

From: Bruce Stenning
Date: Wed Apr 13 2011 - 12:21:44 EST

> Yeah, I'm suspecting there's a loophole in the logic there somewhere.
> I dusted off the 6041 reference card I have here, and played with the cables for a while. Managed to > get one port to stop responding to hot plug fairly quickly, though I'm not sure how/why.
> Then I added a debug printk() to mv_write_main_irq_mask(), with no other changes, and that appears to > have been enough to change the race timing so that I could no longer produce the problem.
> Bruce, here's a slightly-ugly patch that should remove all doubt about races in the irq_mask. Please > apply it, test with it, and let me know here if the issue goes away.
> Thanks

Thanks Mark. I was about to try out some tracing in writelfl because I
suspected the irq mask was getting clobbered somewhere along the way, but
I'd been distracted by other work. I shall try your patch out as soon as
I can, and report back.



Bruce Stenning,
b <dot> stenning <at> indigovision <dot> com

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