2 files changed, 6 insertions, 2 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8a79b976f08a..02425e401a6d 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2759,7 +2759,11 @@ static int ata_dev_set_mode(struct ata_device *dev)
         /* Old CFA may refuse this command, which is just fine */
         if (dev->xfer_shift == ATA_SHIFT_PIO && ata_id_is_cfa(dev->id))
                 err_mask &= ~AC_ERR_DEV;
-
+        /* Some very old devices and some bad newer ones fail any kind of
+           SET_XFERMODE request but support PIO0-2 timings and no IORDY */
+        if (dev->xfer_shift == ATA_SHIFT_PIO && !ata_id_has_iordy(dev->id) &&
+                        dev->pio_mode <= XFER_PIO_2)
+                err_mask &= ~AC_ERR_DEV;
         if (err_mask) {
                 ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
                                "(err_mask=0x%x)\n", err_mask);
diff --git a/include/linux/ata.h b/include/linux/ata.h
index c043c1ccf1c5..40c7af05fdb9 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -358,7 +358,7 @@ struct ata_taskfile {
 #define ata_id_removeable(id)   ((id)[0] & (1 << 7))
 #define ata_id_has_dword_io(id) ((id)[50] & (1 << 0))
 #define ata_id_iordy_disable(id) ((id)[49] & (1 << 10))
-#define ata_id_has_iordy(id) ((id)[49] & (1 << 9))
+#define ata_id_has_iordy(id) ((id)[49] & (1 << 11))
 #define ata_id_u32(id,n)        \
         (((u32) (id)[(n) + 1] << 16) | ((u32) (id)[(n)]))
 #define ata_id_u64(id,n)        \