Crucial said,

  Thank you for contacting us. We know that with our M225 line of SSDs
  you sometimes need to disable NCQ (native command queuing) to avoid
  just the type of errors you're seeing. Our recommendation for the
  M225 is to add libata.force=noncq to your Linux kernel boot options,
  under the kernel ATA library option.

  I have sent your feedback to the engineers working on the C300, and
  asked them to please pass it on to the firmware team. I have been
  notified that they are in the process of testing and finalizing a
  new firmware version, that you can expect to see released around the
  end of April. We’ll keep you posted as to when it will be available
  for download.

So, turn off NCQ on the drive w/ the current firmware revision.

Reported in the following bug.

  https://bugzilla.kernel.org/show_bug.cgi?id=15573Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: lethalwp@scarlet.be
Reported-by: Luke Macken <lmacken@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>