libata: Add special ata_pio_need_iordy() handling for Compact Flash.

According to the Compact Flash specification r4.1, PIO modes 5 and 6
do not use iordy.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 9ae583554c8b..175df54eb664 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2001,6 +2001,10 @@ unsigned int ata_pio_need_iordy(const struct ata_device *adev)
            as the caller should know this */
         if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
                 return 0;
+        /* CF spec. r4.1 Table 22 says no iordy on PIO5 and PIO6.  */
+        if (ata_id_is_cfa(adev->id)
+            && (adev->pio_mode == XFER_PIO_5 || adev->pio_mode == XFER_PIO_6))
+                return 0;
         /* PIO3 and higher it is mandatory */
         if (adev->pio_mode > XFER_PIO_2)
                 return 1;