[PATCH] sata_sil24: update sil24_hardreset()

Use phy debouncing instead of unconditional wait after DEV_RST and
make sil24_hardreset() to request followup SRST as that's the only way
to wait for !BSY.  Note that the original implementation never worked
- if the cached status was !BSY, ata_busy_sleep() finished
immediately; otherwise, it timed out regardless of the actual device
status.

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

1 files changed, 14 insertions, 12 deletions

diff --git a/drivers/scsi/sata_sil24.c b/drivers/scsi/sata_sil24.c
index a39e8d0332c6..4a830903393d 100644
--- a/drivers/scsi/sata_sil24.c
+++ b/drivers/scsi/sata_sil24.c
@@ -591,7 +591,7 @@ static int sil24_hardreset(struct ata_port *ap, unsigned int *class)
 {
         void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
         const char *reason;
-        int tout_msec;
+        int tout_msec, rc;
         u32 tmp;
 
         /* sil24 does the right thing(tm) without any protection */
@@ -605,10 +605,14 @@ static int sil24_hardreset(struct ata_port *ap, unsigned int *class)
         tmp = ata_wait_register(port + PORT_CTRL_STAT,
                                 PORT_CS_DEV_RST, PORT_CS_DEV_RST, 10, tout_msec);
 
-        /* SStatus oscillates between zero and valid status for short
-         * duration after DEV_RST, give it time to settle.
+        /* SStatus oscillates between zero and valid status after
+         * DEV_RST, debounce it.
          */
-        msleep(100);
+        rc = sata_phy_debounce(ap, sata_deb_timing_before_fsrst);
+        if (rc) {
+                reason = "PHY debouncing failed";
+                goto err;
+        }
 
         if (tmp & PORT_CS_DEV_RST) {
                 if (ata_port_offline(ap))
@@ -617,15 +621,13 @@ static int sil24_hardreset(struct ata_port *ap, unsigned int *class)
                 goto err;
         }
 
-        if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
-                reason = "device not ready";
-                goto err;
-        }
-
-        /* sil24 doesn't report device class code after hardreset,
-         * leave *class alone.
+        /* Sil24 doesn't store signature FIS after hardreset, so we
+         * can't wait for BSY to clear.  Some devices take a long time
+         * to get ready and those devices will choke if we don't wait
+         * for BSY clearance here.  Tell libata to perform follow-up
+         * softreset.
          */
-        return 0;
+        return -EAGAIN;
 
  err:
         ata_port_printk(ap, KERN_ERR, "hardreset failed (%s)\n", reason);