ide: add __ide_wait_stat() helper

* Split off checking of the status register from ide_wait_stat() to
  __ide_wait_stat() helper.

* Use the new helper in ide_config_drive_speed().  The only change in the
  functionality is that the function now fails if after 20 sec (WAIT_CMD)
  device is still busy (BUSY_STAT bit is set) while previously instead of
  failing the function continued with checking for the correct device status
  (which would give the device additional 10 usec to clear BUSY_STAT bit).

* Remove stale comment for ide_config_drive_speed().

* Remove duplicate comment for ide_wait_stat() from <linux/ide.h>.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 44 insertions, 52 deletions

diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index cf0678b61161..fb524cf175d5 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -505,25 +505,19 @@ int wait_for_ready (ide_drive_t *drive, int timeout)
  * This routine busy-waits for the drive status to be not "busy".
  * It then checks the status for all of the "good" bits and none
  * of the "bad" bits, and if all is okay it returns 0.  All other
- * cases return 1 after invoking ide_error() -- caller should just return.
+ * cases return error -- caller may then invoke ide_error().
  *
  * This routine should get fixed to not hog the cpu during extra long waits..
  * That could be done by busy-waiting for the first jiffy or two, and then
  * setting a timer to wake up at half second intervals thereafter,
  * until timeout is achieved, before timing out.
  */
-int ide_wait_stat (ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 bad, unsigned long timeout)
+static int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad, unsigned long timeout, u8 *rstat)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        u8 stat;
-        int i;
+        ide_hwif_t *hwif = drive->hwif;
         unsigned long flags;
- 
-        /* bail early if we've exceeded max_failures */
-        if (drive->max_failures && (drive->failures > drive->max_failures)) {
-                *startstop = ide_stopped;
-                return 1;
-        }
+        int i;
+        u8 stat;
 
         udelay(1);      /* spec allows drive 400ns to assert "BUSY" */
         if ((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) {
@@ -541,8 +535,8 @@ int ide_wait_stat (ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 b
                                         break;
 
                                 local_irq_restore(flags);
-                                *startstop = ide_error(drive, "status timeout", stat);
-                                return 1;
+                                *rstat = stat;
+                                return -EBUSY;
                         }
                 }
                 local_irq_restore(flags);
@@ -556,11 +550,39 @@ int ide_wait_stat (ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 b
          */
         for (i = 0; i < 10; i++) {
                 udelay(1);
-                if (OK_STAT((stat = hwif->INB(IDE_STATUS_REG)), good, bad))
+                if (OK_STAT((stat = hwif->INB(IDE_STATUS_REG)), good, bad)) {
+                        *rstat = stat;
                         return 0;
+                }
         }
-        *startstop = ide_error(drive, "status error", stat);
-        return 1;
+        *rstat = stat;
+        return -EFAULT;
+}
+
+/*
+ * In case of error returns error value after doing "*startstop = ide_error()".
+ * The caller should return the updated value of "startstop" in this case,
+ * "startstop" is unchanged when the function returns 0.
+ */
+int ide_wait_stat(ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 bad, unsigned long timeout)
+{
+        int err;
+        u8 stat;
+
+        /* bail early if we've exceeded max_failures */
+        if (drive->max_failures && (drive->failures > drive->max_failures)) {
+                *startstop = ide_stopped;
+                return 1;
+        }
+
+        err = __ide_wait_stat(drive, good, bad, timeout, &stat);
+
+        if (err) {
+                char *s = (err == -EBUSY) ? "status timeout" : "status error";
+                *startstop = ide_error(drive, s, stat);
+        }
+
+        return err;
 }
 
 EXPORT_SYMBOL(ide_wait_stat);
@@ -778,15 +800,10 @@ int ide_driveid_update (ide_drive_t *drive)
 #endif
 }
 
-/*
- * Similar to ide_wait_stat(), except it never calls ide_error internally.
- *
- * const char *msg == consider adding for verbose errors.
- */
-int ide_config_drive_speed (ide_drive_t *drive, u8 speed)
+int ide_config_drive_speed(ide_drive_t *drive, u8 speed)
 {
-        ide_hwif_t *hwif        = HWIF(drive);
-        int     i, error        = 1;
+        ide_hwif_t *hwif = drive->hwif;
+        int error;
         u8 stat;
 
 //      while (HWGROUP(drive)->busy)
@@ -826,35 +843,10 @@ int ide_config_drive_speed (ide_drive_t *drive, u8 speed)
         hwif->OUTBSYNC(drive, WIN_SETFEATURES, IDE_COMMAND_REG);
         if ((IDE_CONTROL_REG) && (drive->quirk_list == 2))
                 hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
-        udelay(1);
-        /*
-         * Wait for drive to become non-BUSY
-         */
-        if ((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) {
-                unsigned long flags, timeout;
-                local_irq_set(flags);
-                timeout = jiffies + WAIT_CMD;
-                while ((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) {
-                        if (time_after(jiffies, timeout))
-                                break;
-                }
-                local_irq_restore(flags);
-        }
 
-        /*
-         * Allow status to settle, then read it again.
-         * A few rare drives vastly violate the 400ns spec here,
-         * so we'll wait up to 10usec for a "good" status
-         * rather than expensively fail things immediately.
-         * This fix courtesy of Matthew Faupel & Niccolo Rigacci.
-         */
-        for (i = 0; i < 10; i++) {
-                udelay(1);
-                if (OK_STAT((stat = hwif->INB(IDE_STATUS_REG)), drive->ready_stat, BUSY_STAT|DRQ_STAT|ERR_STAT)) {
-                        error = 0;
-                        break;
-                }
-        }
+        error = __ide_wait_stat(drive, drive->ready_stat,
+                                BUSY_STAT|DRQ_STAT|ERR_STAT,
+                                WAIT_CMD, &stat);
 
         SELECT_MASK(drive, 0);