libata: fix unexpectedly frozen port after ata_eh_reset()
To work around controllers which can't properly plug events while reset, ata_eh_reset() clears error states and ATA_PFLAG_EH_PENDING after reset but before RESET is marked done. As reset is the final recovery action and full verification of devices including onlineness and classfication match is done afterwards, this shouldn't lead to lost devices or missed hotplug events. Unfortunately, it forgot to thaw the port when clearing EH_PENDING, so if the condition happens after resetting an empty port, the port could be left frozen and EH will end without thawing it, making the port unresponsive to further hotplug events. Thaw if the port is frozen after clearing EH_PENDING. This problem is reported by Bruce Stenning in the following thread. http://thread.gmane.org/gmane.linux.kernel/1123265 stable: I think we should weather this patch a bit longer in -rcX before sending it to -stable. Please wait at least a month after this patch makes upstream. Thanks. -v2: Fixed spelling in the comment per Dave Howorth. Signed-off-by:Tejun Heo <tj@kernel.org> Reported-by:
Bruce Stenning <b.stenning@indigovision.com> Cc: stable@kernel.org Cc: Dave Howorth <dhoworth@mrc-lmb.cam.ac.uk> Signed-off-by:
Jeff Garzik <jgarzik@pobox.com>
parent
59c5f46f
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