ide-cd: Don't warn on bogus block size unless it actually matters.

Frans Pop reported that his CDROM drive reports a blocksize of 2352,
and this causes new warnings due to commit
e8e7b9eb11c34ee18bde8b7011af41938d1ad667 ("ide-cd: fix oops when using
growisofs").

What we're trying to do is make sure that "blocklen >> SECTOR_BITS"
is something the block layer won't choke on.

And for Frans' case "2352 >> SECTOR_BITS" is equal to
"2048 >> SECTOR_BITS", and thats "4".

So warning in this case gives no real benefit.

Reported-by: Frans Pop <elendil@planet.nl>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 4a19686fcfe9..a9a1bfb14e7c 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -876,9 +876,12 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
                 return stat;
 
         /*
-         * Sanity check the given block size
+         * Sanity check the given block size, in so far as making
+         * sure the sectors_per_frame we give to the caller won't
+         * end up being bogus.
          */
         blocklen = be32_to_cpu(capbuf.blocklen);
+        blocklen = (blocklen >> SECTOR_BITS) << SECTOR_BITS;
         switch (blocklen) {
         case 512:
         case 1024: