1 files changed, 42 insertions, 30 deletions

diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 074bb32a4a40..92a6c7bcf527 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -249,12 +249,34 @@ static int ide_scan_pio_blacklist (char *model)
         return -1;
 }
 
+unsigned int ide_pio_cycle_time(ide_drive_t *drive, u8 pio)
+{
+        struct hd_driveid *id = drive->id;
+        int cycle_time = 0;
+
+        if (id->field_valid & 2) {
+                if (id->capability & 8)
+                        cycle_time = id->eide_pio_iordy;
+                else
+                        cycle_time = id->eide_pio;
+        }
+
+        /* conservative "downgrade" for all pre-ATA2 drives */
+        if (pio < 3) {
+                if (cycle_time && cycle_time < ide_pio_timings[pio].cycle_time)
+                        cycle_time = 0; /* use standard timing */
+        }
+
+        return cycle_time ? cycle_time : ide_pio_timings[pio].cycle_time;
+}
+
+EXPORT_SYMBOL_GPL(ide_pio_cycle_time);
+
 /**
  *      ide_get_best_pio_mode   -       get PIO mode from drive
  *      @drive: drive to consider
  *      @mode_wanted: preferred mode
  *      @max_mode: highest allowed mode
- *      @d: PIO data
  *
  *      This routine returns the recommended PIO settings for a given drive,
  *      based on the drive->id information and the ide_pio_blacklist[].
@@ -263,22 +285,18 @@ static int ide_scan_pio_blacklist (char *model)
  *      This is used by most chipset support modules when "auto-tuning".
  */
 
-u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_pio_data_t *d)
+u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
 {
         int pio_mode;
-        int cycle_time = 0;
-        int use_iordy = 0;
         struct hd_driveid* id = drive->id;
         int overridden  = 0;
 
-        if (mode_wanted != 255) {
-                pio_mode = mode_wanted;
-                use_iordy = (pio_mode > 2);
-        } else if (!drive->id) {
-                pio_mode = 0;
-        } else if ((pio_mode = ide_scan_pio_blacklist(id->model)) != -1) {
-                overridden = 1;
-                use_iordy = (pio_mode > 2);
+        if (mode_wanted != 255)
+                return min_t(u8, mode_wanted, max_mode);
+
+        if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0 &&
+            (pio_mode = ide_scan_pio_blacklist(id->model)) != -1) {
+                printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
         } else {
                 pio_mode = id->tPIO;
                 if (pio_mode > 2) {     /* 2 is maximum allowed tPIO value */
@@ -286,9 +304,7 @@ u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_p
                         overridden = 1;
                 }
                 if (id->field_valid & 2) {        /* drive implements ATA2? */
-                        if (id->capability & 8) { /* drive supports use_iordy? */
-                                use_iordy = 1;
-                                cycle_time = id->eide_pio_iordy;
+                        if (id->capability & 8) { /* IORDY supported? */
                                 if (id->eide_pio_modes & 7) {
                                         overridden = 0;
                                         if (id->eide_pio_modes & 4)
@@ -298,31 +314,27 @@ u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_p
                                         else
                                                 pio_mode = 3;
                                 }
-                        } else {
-                                cycle_time = id->eide_pio;
                         }
                 }
 
+                if (overridden)
+                        printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
+                                         drive->name);
+
                 /*
                  * Conservative "downgrade" for all pre-ATA2 drives
                  */
-                if (pio_mode && pio_mode < 4) {
+                if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_DOWNGRADE) == 0 &&
+                    pio_mode && pio_mode < 4) {
                         pio_mode--;
-                        overridden = 1;
-                        if (cycle_time && cycle_time < ide_pio_timings[pio_mode].cycle_time)
-                                cycle_time = 0; /* use standard timing */
+                        printk(KERN_INFO "%s: applying conservative "
+                                         "PIO \"downgrade\"\n", drive->name);
                 }
         }
-        if (pio_mode > max_mode) {
+
+        if (pio_mode > max_mode)
                 pio_mode = max_mode;
-                cycle_time = 0;
-        }
-        if (d) {
-                d->pio_mode = pio_mode;
-                d->cycle_time = cycle_time ? cycle_time : ide_pio_timings[pio_mode].cycle_time;
-                d->use_iordy = use_iordy;
-                d->overridden = overridden;
-        }
+
         return pio_mode;
 }