[PATCH] libata: ignore CFA signature while sanity-checking an ATAPI device

0x848a in ID word 0 indicates CFA device iff the ID data is obtained from
IDENTIFY DEVICE.  For ATAPI devices, 0x848a in ID work 0 indicates valid
ATAPI device.  Fix sanity check in ata_dev_read_id() such that ATAPI
devices reporting 0x848a in ID word 0 is not handled as error.

The problem is identified by J.A.  Magallon with HL-DT-ST DVDRAM GSA-4120B.

Signed-off-by: Tejun Helo <htejun@gmail.com>
Cc: J.A. Magallon <jamagallon@ono.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 73dd6c8deede..427b73a3886a 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1256,10 +1256,15 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
         swap_buf_le16(id, ATA_ID_WORDS);
 
         /* sanity check */
-        if ((class == ATA_DEV_ATA) != (ata_id_is_ata(id) | ata_id_is_cfa(id))) {
-                rc = -EINVAL;
-                reason = "device reports illegal type";
-                goto err_out;
+        rc = -EINVAL;
+        reason = "device reports illegal type";
+
+        if (class == ATA_DEV_ATA) {
+                if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
+                        goto err_out;
+        } else {
+                if (ata_id_is_ata(id))
+                        goto err_out;
         }
 
         if (post_reset && class == ATA_DEV_ATA) {