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authorAlan Cox <alan@lxorguk.ukuu.org.uk>2007-07-31 14:01:48 +0100
committerJeff Garzik <jeff@garzik.org>2007-10-12 14:55:32 -0400
commit0bc2a79a2002e3cc1b514c100b6c576983da6a90 (patch)
tree7669cfe54f3cf5125be440c5c9e84d29cec27294
parente3667ebf857ba744b5211c90d46f6a17dd9a2479 (diff)
libata: Correct IORDY handling
Debugging a report of a problem with an ancient solid state disk showed up some problems in the IORDY handling 1. We check the wrong bit to see if the device has IORDY 2. Even then some ancient creaking piles of crap don't support SETXFER at all. The cases it fixes are obscure and the risk of side effects is slight but possible. This also moves us slightly closer to supporting original MFM/RLL disks with libata. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
-rw-r--r--drivers/ata/libata-core.c6
-rw-r--r--include/linux/ata.h2
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8a79b976f08..02425e401a6 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 c043c1ccf1c..40c7af05fdb 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) \