ATA does not only have the WCACHE enabled bit in identify word 85, but also
a WCACHE supported bit in word 82. While the Linux kernel is fine with the
latter at least hdparm also needs the former before correctly displaying
the cache settings. There's also a non-zero chance other operating systems
are more picky in their volatile write cache detection.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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