libata: cosmetic clean up / reorganization of ata_eh_reset()

Clean up and reorganize ata_eh_reset() to ease further changes.

* Cache ARRAY_SIZE(ata_eh_reset_timeouts) in @max_tries.
* Cache link->flags in @lflags.
* Move failure handling block to the end of the function and unnest
  both success and failure handling blocks.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 53b2348..dae2174 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2065,16 +2065,19 @@ int ata_eh_reset(struct ata_link *link, int classify,
                 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
                 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
+       const int max_tries = ARRAY_SIZE(ata_eh_reset_timeouts);
        struct ata_port *ap = link->ap;
        struct ata_eh_context *ehc = &link->eh_context;
        unsigned int *classes = ehc->classes;
+       unsigned int lflags = link->flags;
        int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
        int try = 0;
        struct ata_device *dev;
-       unsigned long deadline;
+       unsigned long deadline, now;
        unsigned int tmp_action;
        ata_reset_fn_t reset;
        unsigned long flags;
+       u32 sstatus;
        int rc;
 
        /* about to reset */
@@ -2106,7 +2109,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
        /* Determine which reset to use and record in ehc->i.action.
         * prereset() may examine and modify it.
         */
-       if (softreset && (!hardreset || (!(link->flags & ATA_LFLAG_NO_SRST) &&
+       if (softreset && (!hardreset || (!(lflags & ATA_LFLAG_NO_SRST) &&
                                         !sata_set_spd_needed(link) &&
                                         !(ehc->i.action & ATA_EH_HARDRESET))))
                tmp_action = ATA_EH_SOFTRESET;
@@ -2188,7 +2191,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
                rc = ata_do_reset(link, reset, classes, deadline);
 
                if (rc == 0 && classify && classes[0] == ATA_DEV_UNKNOWN &&
-                   !(link->flags & ATA_LFLAG_ASSUME_CLASS)) {
+                   !(lflags & ATA_LFLAG_ASSUME_CLASS)) {
                        ata_link_printk(link, KERN_ERR,
                                        "classification failed\n");
                        rc = -EINVAL;
@@ -2196,67 +2199,42 @@ int ata_eh_reset(struct ata_link *link, int classify,
                }
        }
 
-       /* if we skipped follow-up srst, clear rc */
-       if (rc == -EAGAIN)
-               rc = 0;
-
-       if (rc && rc != -ERESTART && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
-               unsigned long now = jiffies;
+       /* -EAGAIN can happen if we skipped followup SRST */
+       if (rc && rc != -EAGAIN)
+               goto fail;
 
-               if (time_before(now, deadline)) {
-                       unsigned long delta = deadline - now;
-
-                       ata_link_printk(link, KERN_WARNING, "reset failed "
-                               "(errno=%d), retrying in %u secs\n",
-                               rc, (jiffies_to_msecs(delta) + 999) / 1000);
+       ata_link_for_each_dev(dev, link) {
+               /* After the reset, the device state is PIO 0 and the
+                * controller state is undefined.  Reset also wakes up
+                * drives from sleeping mode.
+                */
+               dev->pio_mode = XFER_PIO_0;
+               dev->flags &= ~ATA_DFLAG_SLEEPING;
 
-                       while (delta)
-                               delta = schedule_timeout_uninterruptible(delta);
-               }
+               if (ata_link_offline(link))
+                       continue;
 
-               if (rc == -EPIPE ||
-                   try == ARRAY_SIZE(ata_eh_reset_timeouts) - 1)
-                       sata_down_spd_limit(link);
-               if (hardreset)
-                       reset = hardreset;
-               goto retry;
+               /* apply class override and convert UNKNOWN to NONE */
+               if (lflags & ATA_LFLAG_ASSUME_ATA)
+                       classes[dev->devno] = ATA_DEV_ATA;
+               else if (lflags & ATA_LFLAG_ASSUME_SEMB)
+                       classes[dev->devno] = ATA_DEV_SEMB_UNSUP; /* not yet */
+               else if (classes[dev->devno] == ATA_DEV_UNKNOWN)
+                       classes[dev->devno] = ATA_DEV_NONE;
        }
 
-       if (rc == 0) {
-               u32 sstatus;
-
-               ata_link_for_each_dev(dev, link) {
-                       /* After the reset, the device state is PIO 0
-                        * and the controller state is undefined.
-                        * Reset also wakes up drives from sleeping
-                        * mode.
-                        */
-                       dev->pio_mode = XFER_PIO_0;
-                       dev->flags &= ~ATA_DFLAG_SLEEPING;
-
-                       if (ata_link_offline(link))
-                               continue;
-
-                       /* apply class override and convert UNKNOWN to NONE */
-                       if (link->flags & ATA_LFLAG_ASSUME_ATA)
-                               classes[dev->devno] = ATA_DEV_ATA;
-                       else if (link->flags & ATA_LFLAG_ASSUME_SEMB)
-                               classes[dev->devno] = ATA_DEV_SEMB_UNSUP; /* not yet */
-                       else if (classes[dev->devno] == ATA_DEV_UNKNOWN)
-                               classes[dev->devno] = ATA_DEV_NONE;
-               }
+       /* record current link speed */
+       if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
+               link->sata_spd = (sstatus >> 4) & 0xf;
 
-               /* record current link speed */
-               if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
-                       link->sata_spd = (sstatus >> 4) & 0xf;
+       if (postreset)
+               postreset(link, classes);
 
-               if (postreset)
-                       postreset(link, classes);
+       /* reset successful, schedule revalidation */
+       ata_eh_done(link, NULL, ehc->i.action & ATA_EH_RESET_MASK);
+       ehc->i.action |= ATA_EH_REVALIDATE;
 
-               /* reset successful, schedule revalidation */
-               ata_eh_done(link, NULL, ehc->i.action & ATA_EH_RESET_MASK);
-               ehc->i.action |= ATA_EH_REVALIDATE;
-       }
+       rc = 0;
  out:
        /* clear hotplug flag */
        ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
@@ -2266,6 +2244,28 @@ int ata_eh_reset(struct ata_link *link, int classify,
        spin_unlock_irqrestore(ap->lock, flags);
 
        return rc;
+
+ fail:
+       if (rc == -ERESTART || try >= max_tries)
+               goto out;
+
+       now = jiffies;
+       if (time_before(now, deadline)) {
+               unsigned long delta = deadline - now;
+
+               ata_link_printk(link, KERN_WARNING, "reset failed "
+                               "(errno=%d), retrying in %u secs\n",
+                               rc, (jiffies_to_msecs(delta) + 999) / 1000);
+
+               while (delta)
+                       delta = schedule_timeout_uninterruptible(delta);
+       }
+
+       if (rc == -EPIPE || try == max_tries - 1)
+               sata_down_spd_limit(link);
+       if (hardreset)
+               reset = hardreset;
+       goto retry;
 }
 
 static int ata_eh_revalidate_and_attach(struct ata_link *link,