libata: restructure SFF post-reset readiness waits

Previously, post-softreset readiness is waited as follows.

1. ata_sff_wait_after_reset() waits for 150ms and then for
   ATA_TMOUT_FF_WAIT if status is 0xff and other conditions meet.

2. ata_bus_softreset() finishes with -ENODEV if status is still 0xff.
   If not, continue to #3.

3. ata_bus_post_reset() waits readiness of dev0 and/or dev1 depending
   on devmask using ata_sff_wait_ready().

And for post-hardreset readiness,

1. ata_sff_wait_after_reset() waits for 150ms and then for
   ATA_TMOUT_FF_WAIT if status is 0xff and other conditions meet.

2. sata_sff_hardreset waits for device readiness using
   ata_sff_wait_ready().

This patch merges and unifies post-reset readiness waits into
ata_sff_wait_ready() and ata_sff_wait_after_reset().

ATA_TMOUT_FF_WAIT handling is merged into ata_sff_wait_ready().  If TF
status is 0xff, link status is unknown and the port is SATA, it will
continue polling till ATA_TMOUT_FF_WAIT.

ata_sff_wait_after_reset() is updated to perform the following steps.

1. waits for 150ms.

2. waits for dev0 readiness using ata_sff_wait_ready().  Note that
   this is done regardless of devmask, as ata_sff_wait_ready() handles
   0xff status correctly, this preserves the original behavior except
   that it may wait longer after softreset if link is online but
   status is 0xff.  This behavior change is very unlikely to cause any
   actual difference and is intended.  It brings softreset behavior to
   that of hardreset.

3. waits for dev1 readiness just the same way ata_bus_post_reset() did.

Now both soft and hard resets call ata_sff_wait_after_reset() after
reset to wait for readiness after resets.  As
ata_sff_wait_after_reset() contains calls to ->sff_dev_select(),
explicit call near the end of sata_sff_hardreset() is removed.

This change makes reset implementation simpler and more consistent.

While at it, make the magical 150ms wait post-reset wait duration a
constant and ata_sff_wait_ready() and ata_sff_wait_after_reset() take
@link instead of @ap.  This is to make them consistent with other
reset helpers and ease core changes.

pata_scc is updated accordingly.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 939dc1d4e50d..45a67a9ad8ab 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1302,10 +1302,8 @@ static int ahci_do_softreset(struct ata_link *link, unsigned int *class,
         tf.ctl &= ~ATA_SRST;
         ahci_exec_polled_cmd(ap, pmp, &tf, 0, 0, 0);
 
-        /* wait a while before checking status */
-        ata_sff_wait_after_reset(ap, deadline);
-
-        rc = ata_sff_wait_ready(ap, deadline);
+        /* wait for link to become ready */
+        rc = ata_sff_wait_after_reset(link, 1, deadline);
         /* link occupied, -ENODEV too is an error */
         if (rc) {
                 reason = "device not ready";
@@ -1415,9 +1413,6 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
         if (rc || ata_link_offline(link))
                 return rc;
 
-        /* spec mandates ">= 2ms" before checking status */
-        msleep(150);
-
         /* The pseudo configuration device on SIMG4726 attached to
          * ASUS P5W-DH Deluxe doesn't send signature FIS after
          * hardreset if no device is attached to the first downstream
@@ -1431,7 +1426,7 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
          * have to be reset again.  For most cases, this should
          * suffice while making probing snappish enough.
          */
-        rc = ata_sff_wait_ready(ap, jiffies + 2 * HZ);
+        rc = ata_sff_wait_after_reset(link, 1, jiffies + 2 * HZ);
         if (rc)
                 ahci_kick_engine(ap, 0);