3 files changed, 27 insertions, 1 deletions

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index f371b0de314f..fdd04bcd5568 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1378,6 +1378,9 @@ int ide_host_register(struct ide_host *host, const struct ide_port_info *d,
 
                 ide_init_port(hwif, i & 1, d);
                 ide_port_cable_detect(hwif);
+
+                hwif->port_flags |= IDE_PFLAG_PROBING;
+
                 ide_port_init_devices(hwif);
         }
 
@@ -1388,6 +1391,8 @@ int ide_host_register(struct ide_host *host, const struct ide_port_info *d,
                 if (ide_probe_port(hwif) == 0)
                         hwif->present = 1;
 
+                hwif->port_flags &= ~IDE_PFLAG_PROBING;
+
                 if ((hwif->host_flags & IDE_HFLAG_4DRIVES) == 0 ||
                     hwif->mate == NULL || hwif->mate->present == 0) {
                         if (ide_register_port(hwif)) {
@@ -1569,11 +1574,20 @@ EXPORT_SYMBOL_GPL(ide_host_remove);
 
 void ide_port_scan(ide_hwif_t *hwif)
 {
+        int rc;
+
         ide_port_apply_params(hwif);
         ide_port_cable_detect(hwif);
+
+        hwif->port_flags |= IDE_PFLAG_PROBING;
+
         ide_port_init_devices(hwif);
 
-        if (ide_probe_port(hwif) < 0)
+        rc = ide_probe_port(hwif);
+
+        hwif->port_flags &= ~IDE_PFLAG_PROBING;
+
+        if (rc < 0)
                 return;
 
         hwif->present = 1;
diff --git a/drivers/ide/ide-xfer-mode.c b/drivers/ide/ide-xfer-mode.c
index 0b47ca139079..46d203ce60cc 100644
--- a/drivers/ide/ide-xfer-mode.c
+++ b/drivers/ide/ide-xfer-mode.c
@@ -109,6 +109,12 @@ EXPORT_SYMBOL_GPL(ide_get_best_pio_mode);
 
 int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
 {
+        /*
+         * IORDY may lead to controller lock up on certain controllers
+         * if the port is not occupied.
+         */
+        if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
+                return 0;
         return ata_id_pio_need_iordy(drive->id, pio);
 }
 EXPORT_SYMBOL_GPL(ide_pio_need_iordy);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 8c7f5e50e912..8771d49aa874 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -661,6 +661,10 @@ struct ide_dma_ops {
         u8      (*dma_sff_read_status)(struct hwif_s *);
 };
 
+enum {
+        IDE_PFLAG_PROBING               = (1 << 0),
+};
+
 struct ide_host;
 
 typedef struct hwif_s {
@@ -677,6 +681,8 @@ typedef struct hwif_s {
 
         ide_drive_t     *devices[MAX_DRIVES + 1];
 
+        unsigned long   port_flags;
+
         u8 major;       /* our major number */
         u8 index;       /* 0 for ide0; 1 for ide1; ... */
         u8 channel;     /* for dual-port chips: 0=primary, 1=secondary */