pata_it821x: Update RDC UDMA handling
[safe/jmp/linux-2.6] / drivers / ata / libata-core.c
index 8824c8d..71218d7 100644 (file)
@@ -56,6 +56,7 @@
 #include <linux/workqueue.h>
 #include <linux/scatterlist.h>
 #include <linux/io.h>
+#include <linux/async.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
@@ -163,43 +164,119 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 
-/*
- * Iterator helpers.  Don't use directly.
+/**
+ *     ata_link_next - link iteration helper
+ *     @link: the previous link, NULL to start
+ *     @ap: ATA port containing links to iterate
+ *     @mode: iteration mode, one of ATA_LITER_*
  *
- * LOCKING:
- * Host lock or EH context.
+ *     LOCKING:
+ *     Host lock or EH context.
+ *
+ *     RETURNS:
+ *     Pointer to the next link.
  */
-struct ata_link *__ata_port_next_link(struct ata_port *ap,
-                                     struct ata_link *link, bool dev_only)
+struct ata_link *ata_link_next(struct ata_link *link, struct ata_port *ap,
+                              enum ata_link_iter_mode mode)
 {
+       BUG_ON(mode != ATA_LITER_EDGE &&
+              mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);
+
        /* NULL link indicates start of iteration */
-       if (!link) {
-               if (dev_only && sata_pmp_attached(ap))
-                       return ap->pmp_link;
-               return &ap->link;
-       }
+       if (!link)
+               switch (mode) {
+               case ATA_LITER_EDGE:
+               case ATA_LITER_PMP_FIRST:
+                       if (sata_pmp_attached(ap))
+                               return ap->pmp_link;
+                       /* fall through */
+               case ATA_LITER_HOST_FIRST:
+                       return &ap->link;
+               }
 
-       /* we just iterated over the host master link, what's next? */
-       if (link == &ap->link) {
-               if (!sata_pmp_attached(ap)) {
-                       if (unlikely(ap->slave_link) && !dev_only)
+       /* we just iterated over the host link, what's next? */
+       if (link == &ap->link)
+               switch (mode) {
+               case ATA_LITER_HOST_FIRST:
+                       if (sata_pmp_attached(ap))
+                               return ap->pmp_link;
+                       /* fall through */
+               case ATA_LITER_PMP_FIRST:
+                       if (unlikely(ap->slave_link))
                                return ap->slave_link;
+                       /* fall through */
+               case ATA_LITER_EDGE:
                        return NULL;
                }
-               return ap->pmp_link;
-       }
 
        /* slave_link excludes PMP */
        if (unlikely(link == ap->slave_link))
                return NULL;
 
-       /* iterate to the next PMP link */
+       /* we were over a PMP link */
        if (++link < ap->pmp_link + ap->nr_pmp_links)
                return link;
+
+       if (mode == ATA_LITER_PMP_FIRST)
+               return &ap->link;
+
        return NULL;
 }
 
 /**
+ *     ata_dev_next - device iteration helper
+ *     @dev: the previous device, NULL to start
+ *     @link: ATA link containing devices to iterate
+ *     @mode: iteration mode, one of ATA_DITER_*
+ *
+ *     LOCKING:
+ *     Host lock or EH context.
+ *
+ *     RETURNS:
+ *     Pointer to the next device.
+ */
+struct ata_device *ata_dev_next(struct ata_device *dev, struct ata_link *link,
+                               enum ata_dev_iter_mode mode)
+{
+       BUG_ON(mode != ATA_DITER_ENABLED && mode != ATA_DITER_ENABLED_REVERSE &&
+              mode != ATA_DITER_ALL && mode != ATA_DITER_ALL_REVERSE);
+
+       /* NULL dev indicates start of iteration */
+       if (!dev)
+               switch (mode) {
+               case ATA_DITER_ENABLED:
+               case ATA_DITER_ALL:
+                       dev = link->device;
+                       goto check;
+               case ATA_DITER_ENABLED_REVERSE:
+               case ATA_DITER_ALL_REVERSE:
+                       dev = link->device + ata_link_max_devices(link) - 1;
+                       goto check;
+               }
+
+ next:
+       /* move to the next one */
+       switch (mode) {
+       case ATA_DITER_ENABLED:
+       case ATA_DITER_ALL:
+               if (++dev < link->device + ata_link_max_devices(link))
+                       goto check;
+               return NULL;
+       case ATA_DITER_ENABLED_REVERSE:
+       case ATA_DITER_ALL_REVERSE:
+               if (--dev >= link->device)
+                       goto check;
+               return NULL;
+       }
+
+ check:
+       if ((mode == ATA_DITER_ENABLED || mode == ATA_DITER_ENABLED_REVERSE) &&
+           !ata_dev_enabled(dev))
+               goto next;
+       return dev;
+}
+
+/**
  *     ata_dev_phys_link - find physical link for a device
  *     @dev: ATA device to look up physical link for
  *
@@ -612,7 +689,7 @@ u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
                if (tf->flags & ATA_TFLAG_LBA48) {
                        block |= (u64)tf->hob_lbah << 40;
                        block |= (u64)tf->hob_lbam << 32;
-                       block |= tf->hob_lbal << 24;
+                       block |= (u64)tf->hob_lbal << 24;
                } else
                        block |= (tf->device & 0xf) << 24;
 
@@ -930,6 +1007,7 @@ static const char *sata_spd_string(unsigned int spd)
        static const char * const spd_str[] = {
                "1.5 Gbps",
                "3.0 Gbps",
+               "6.0 Gbps",
        };
 
        if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
@@ -1107,8 +1185,8 @@ static void ata_lpm_enable(struct ata_host *host)
 
        for (i = 0; i < host->n_ports; i++) {
                ap = host->ports[i];
-               ata_port_for_each_link(link, ap) {
-                       ata_link_for_each_dev(dev, link)
+               ata_for_each_link(link, ap, EDGE) {
+                       ata_for_each_dev(dev, link, ALL)
                                ata_dev_disable_pm(dev);
                }
        }
@@ -1712,6 +1790,8 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
        else
                tag = 0;
 
+       if (test_and_set_bit(tag, &ap->qc_allocated))
+               BUG();
        qc = __ata_qc_from_tag(ap, tag);
 
        qc->tag = tag;
@@ -1921,6 +2001,10 @@ unsigned int ata_pio_need_iordy(const struct ata_device *adev)
           as the caller should know this */
        if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
                return 0;
+       /* CF spec. r4.1 Table 22 says no iordy on PIO5 and PIO6.  */
+       if (ata_id_is_cfa(adev->id)
+           && (adev->pio_mode == XFER_PIO_5 || adev->pio_mode == XFER_PIO_6))
+               return 0;
        /* PIO3 and higher it is mandatory */
        if (adev->pio_mode > XFER_PIO_2)
                return 1;
@@ -2158,6 +2242,10 @@ retry:
 static inline u8 ata_dev_knobble(struct ata_device *dev)
 {
        struct ata_port *ap = dev->link->ap;
+
+       if (ata_dev_blacklisted(dev) & ATA_HORKAGE_BRIDGE_OK)
+               return 0;
+
        return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
 }
 
@@ -2486,6 +2574,13 @@ int ata_dev_configure(struct ata_device *dev)
                }
        }
 
+       if ((dev->horkage & ATA_HORKAGE_FIRMWARE_WARN) && print_info) {
+               ata_dev_printk(dev, KERN_WARNING, "WARNING: device requires "
+                              "firmware update to be fully functional.\n");
+               ata_dev_printk(dev, KERN_WARNING, "         contact the vendor "
+                              "or visit http://ata.wiki.kernel.org.\n");
+       }
+
        return 0;
 
 err_out_nosup:
@@ -2581,11 +2676,11 @@ int ata_bus_probe(struct ata_port *ap)
 
        ata_port_probe(ap);
 
-       ata_link_for_each_dev(dev, &ap->link)
+       ata_for_each_dev(dev, &ap->link, ALL)
                tries[dev->devno] = ATA_PROBE_MAX_TRIES;
 
  retry:
-       ata_link_for_each_dev(dev, &ap->link) {
+       ata_for_each_dev(dev, &ap->link, ALL) {
                /* If we issue an SRST then an ATA drive (not ATAPI)
                 * may change configuration and be in PIO0 timing. If
                 * we do a hard reset (or are coming from power on)
@@ -2607,7 +2702,7 @@ int ata_bus_probe(struct ata_port *ap)
        /* reset and determine device classes */
        ap->ops->phy_reset(ap);
 
-       ata_link_for_each_dev(dev, &ap->link) {
+       ata_for_each_dev(dev, &ap->link, ALL) {
                if (!(ap->flags & ATA_FLAG_DISABLED) &&
                    dev->class != ATA_DEV_UNKNOWN)
                        classes[dev->devno] = dev->class;
@@ -2623,7 +2718,7 @@ int ata_bus_probe(struct ata_port *ap)
           specific sequence bass-ackwards so that PDIAG- is released by
           the slave device */
 
-       ata_link_for_each_dev_reverse(dev, &ap->link) {
+       ata_for_each_dev(dev, &ap->link, ALL_REVERSE) {
                if (tries[dev->devno])
                        dev->class = classes[dev->devno];
 
@@ -2640,24 +2735,19 @@ int ata_bus_probe(struct ata_port *ap)
        if (ap->ops->cable_detect)
                ap->cbl = ap->ops->cable_detect(ap);
 
-       /* We may have SATA bridge glue hiding here irrespective of the
-          reported cable types and sensed types */
-       ata_link_for_each_dev(dev, &ap->link) {
-               if (!ata_dev_enabled(dev))
-                       continue;
-               /* SATA drives indicate we have a bridge. We don't know which
-                  end of the link the bridge is which is a problem */
+       /* We may have SATA bridge glue hiding here irrespective of
+        * the reported cable types and sensed types.  When SATA
+        * drives indicate we have a bridge, we don't know which end
+        * of the link the bridge is which is a problem.
+        */
+       ata_for_each_dev(dev, &ap->link, ENABLED)
                if (ata_id_is_sata(dev->id))
                        ap->cbl = ATA_CBL_SATA;
-       }
 
        /* After the identify sequence we can now set up the devices. We do
           this in the normal order so that the user doesn't get confused */
 
-       ata_link_for_each_dev(dev, &ap->link) {
-               if (!ata_dev_enabled(dev))
-                       continue;
-
+       ata_for_each_dev(dev, &ap->link, ENABLED) {
                ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
                rc = ata_dev_configure(dev);
                ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
@@ -2670,9 +2760,8 @@ int ata_bus_probe(struct ata_port *ap)
        if (rc)
                goto fail;
 
-       ata_link_for_each_dev(dev, &ap->link)
-               if (ata_dev_enabled(dev))
-                       return 0;
+       ata_for_each_dev(dev, &ap->link, ENABLED)
+               return 0;
 
        /* no device present, disable port */
        ata_port_disable(ap);
@@ -3318,13 +3407,10 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
        int rc = 0, used_dma = 0, found = 0;
 
        /* step 1: calculate xfer_mask */
-       ata_link_for_each_dev(dev, link) {
+       ata_for_each_dev(dev, link, ENABLED) {
                unsigned long pio_mask, dma_mask;
                unsigned int mode_mask;
 
-               if (!ata_dev_enabled(dev))
-                       continue;
-
                mode_mask = ATA_DMA_MASK_ATA;
                if (dev->class == ATA_DEV_ATAPI)
                        mode_mask = ATA_DMA_MASK_ATAPI;
@@ -3353,10 +3439,7 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
                goto out;
 
        /* step 2: always set host PIO timings */
-       ata_link_for_each_dev(dev, link) {
-               if (!ata_dev_enabled(dev))
-                       continue;
-
+       ata_for_each_dev(dev, link, ENABLED) {
                if (dev->pio_mode == 0xff) {
                        ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
                        rc = -EINVAL;
@@ -3370,8 +3453,8 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
        }
 
        /* step 3: set host DMA timings */
-       ata_link_for_each_dev(dev, link) {
-               if (!ata_dev_enabled(dev) || !ata_dma_enabled(dev))
+       ata_for_each_dev(dev, link, ENABLED) {
+               if (!ata_dma_enabled(dev))
                        continue;
 
                dev->xfer_mode = dev->dma_mode;
@@ -3381,11 +3464,7 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
        }
 
        /* step 4: update devices' xfer mode */
-       ata_link_for_each_dev(dev, link) {
-               /* don't update suspended devices' xfer mode */
-               if (!ata_dev_enabled(dev))
-                       continue;
-
+       ata_for_each_dev(dev, link, ENABLED) {
                rc = ata_dev_set_mode(dev);
                if (rc)
                        goto out;
@@ -4020,6 +4099,7 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 
        /* Weird ATAPI devices */
        { "TORiSAN DVD-ROM DRD-N216", NULL,     ATA_HORKAGE_MAX_SEC_128 },
+       { "QUANTUM DAT    DAT72-000", NULL,     ATA_HORKAGE_ATAPI_MOD16_DMA },
 
        /* Devices we expect to fail diagnostics */
 
@@ -4034,6 +4114,74 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
        { "Maxtor 7V300F0",     "VA111630",     ATA_HORKAGE_NONCQ },
        { "ST380817AS",         "3.42",         ATA_HORKAGE_NONCQ },
        { "ST3160023AS",        "3.42",         ATA_HORKAGE_NONCQ },
+       { "OCZ CORE_SSD",       "02.10104",     ATA_HORKAGE_NONCQ },
+
+       /* Seagate NCQ + FLUSH CACHE firmware bug */
+       { "ST31500341AS",       "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31500341AS",       "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31500341AS",       "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31500341AS",       "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31500341AS",       "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+
+       { "ST31000333AS",       "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31000333AS",       "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31000333AS",       "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31000333AS",       "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST31000333AS",       "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+
+       { "ST3640623AS",        "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640623AS",        "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640623AS",        "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640623AS",        "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640623AS",        "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+
+       { "ST3640323AS",        "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640323AS",        "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640323AS",        "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640323AS",        "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3640323AS",        "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+
+       { "ST3320813AS",        "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320813AS",        "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320813AS",        "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320813AS",        "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320813AS",        "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+
+       { "ST3320613AS",        "SD15",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320613AS",        "SD16",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320613AS",        "SD17",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320613AS",        "SD18",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
+       { "ST3320613AS",        "SD19",         ATA_HORKAGE_NONCQ |
+                                               ATA_HORKAGE_FIRMWARE_WARN },
 
        /* Blacklist entries taken from Silicon Image 3124/3132
           Windows driver .inf file - also several Linux problem reports */
@@ -4062,6 +4210,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
        { "TSSTcorp CDDVDW SH-S202N", "SB00",     ATA_HORKAGE_IVB, },
        { "TSSTcorp CDDVDW SH-S202N", "SB01",     ATA_HORKAGE_IVB, },
 
+       /* Devices that do not need bridging limits applied */
+       { "MTRON MSP-SATA*",            NULL,   ATA_HORKAGE_BRIDGE_OK, },
+
        /* End Marker */
        { }
 };
@@ -4179,9 +4330,9 @@ static int cable_is_40wire(struct ata_port *ap)
         * - if you have a non detect capable drive you don't want it
         *   to colour the choice
         */
-       ata_port_for_each_link(link, ap) {
-               ata_link_for_each_dev(dev, link) {
-                       if (ata_dev_enabled(dev) && !ata_is_40wire(dev))
+       ata_for_each_link(link, ap, EDGE) {
+               ata_for_each_dev(dev, link, ENABLED) {
+                       if (!ata_is_40wire(dev))
                                return 0;
                }
        }
@@ -4405,7 +4556,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
        struct scatterlist *sg = qc->sg;
        int dir = qc->dma_dir;
 
-       WARN_ON(sg == NULL);
+       WARN_ON_ONCE(sg == NULL);
 
        VPRINTK("unmapping %u sg elements\n", qc->n_elem);
 
@@ -4437,7 +4588,8 @@ int atapi_check_dma(struct ata_queued_cmd *qc)
        /* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
         * few ATAPI devices choke on such DMA requests.
         */
-       if (unlikely(qc->nbytes & 15))
+       if (!(qc->dev->horkage & ATA_HORKAGE_ATAPI_MOD16_DMA) &&
+           unlikely(qc->nbytes & 15))
                return 1;
 
        if (ap->ops->check_atapi_dma)
@@ -4554,28 +4706,54 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 }
 
 /**
- *     ata_qc_new_init - Request an available ATA command, and initialize it
+ *     ata_qc_new - Request an available ATA command, for queueing
+ *     @ap: Port associated with device @dev
  *     @dev: Device from whom we request an available command structure
- *     @tag: command tag
  *
  *     LOCKING:
  *     None.
  */
 
-struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
+static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
 {
-       struct ata_port *ap = dev->link->ap;
-       struct ata_queued_cmd *qc;
+       struct ata_queued_cmd *qc = NULL;
+       unsigned int i;
 
+       /* no command while frozen */
        if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
                return NULL;
 
-       qc = __ata_qc_from_tag(ap, tag);
+       /* the last tag is reserved for internal command. */
+       for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
+               if (!test_and_set_bit(i, &ap->qc_allocated)) {
+                       qc = __ata_qc_from_tag(ap, i);
+                       break;
+               }
+
+       if (qc)
+               qc->tag = i;
+
+       return qc;
+}
+
+/**
+ *     ata_qc_new_init - Request an available ATA command, and initialize it
+ *     @dev: Device from whom we request an available command structure
+ *
+ *     LOCKING:
+ *     None.
+ */
+
+struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
+{
+       struct ata_port *ap = dev->link->ap;
+       struct ata_queued_cmd *qc;
+
+       qc = ata_qc_new(ap);
        if (qc) {
                qc->scsicmd = NULL;
                qc->ap = ap;
                qc->dev = dev;
-               qc->tag = tag;
 
                ata_qc_reinit(qc);
        }
@@ -4583,13 +4761,38 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
        return qc;
 }
 
+/**
+ *     ata_qc_free - free unused ata_queued_cmd
+ *     @qc: Command to complete
+ *
+ *     Designed to free unused ata_queued_cmd object
+ *     in case something prevents using it.
+ *
+ *     LOCKING:
+ *     spin_lock_irqsave(host lock)
+ */
+void ata_qc_free(struct ata_queued_cmd *qc)
+{
+       struct ata_port *ap = qc->ap;
+       unsigned int tag;
+
+       WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
+
+       qc->flags = 0;
+       tag = qc->tag;
+       if (likely(ata_tag_valid(tag))) {
+               qc->tag = ATA_TAG_POISON;
+               clear_bit(tag, &ap->qc_allocated);
+       }
+}
+
 void __ata_qc_complete(struct ata_queued_cmd *qc)
 {
        struct ata_port *ap = qc->ap;
        struct ata_link *link = qc->dev->link;
 
-       WARN_ON(qc == NULL);    /* ata_qc_from_tag _might_ return NULL */
-       WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
+       WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
+       WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
 
        if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
                ata_sg_clean(qc);
@@ -4675,7 +4878,7 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                struct ata_device *dev = qc->dev;
                struct ata_eh_info *ehi = &dev->link->eh_info;
 
-               WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
+               WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
 
                if (unlikely(qc->err_mask))
                        qc->flags |= ATA_QCFLAG_FAILED;
@@ -4797,16 +5000,16 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
         * check is skipped for old EH because it reuses active qc to
         * request ATAPI sense.
         */
-       WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
+       WARN_ON_ONCE(ap->ops->error_handler && ata_tag_valid(link->active_tag));
 
        if (ata_is_ncq(prot)) {
-               WARN_ON(link->sactive & (1 << qc->tag));
+               WARN_ON_ONCE(link->sactive & (1 << qc->tag));
 
                if (!link->sactive)
                        ap->nr_active_links++;
                link->sactive |= 1 << qc->tag;
        } else {
-               WARN_ON(link->sactive);
+               WARN_ON_ONCE(link->sactive);
 
                ap->nr_active_links++;
                link->active_tag = qc->tag;
@@ -5081,7 +5284,7 @@ static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
                }
 
                ap->pflags |= ATA_PFLAG_PM_PENDING;
-               __ata_port_for_each_link(link, ap) {
+               ata_for_each_link(link, ap, HOST_FIRST) {
                        link->eh_info.action |= action;
                        link->eh_info.flags |= ehi_flags;
                }
@@ -5712,6 +5915,65 @@ void ata_host_init(struct ata_host *host, struct device *dev,
        host->ops = ops;
 }
 
+
+static void async_port_probe(void *data, async_cookie_t cookie)
+{
+       int rc;
+       struct ata_port *ap = data;
+
+       /*
+        * If we're not allowed to scan this host in parallel,
+        * we need to wait until all previous scans have completed
+        * before going further.
+        * Jeff Garzik says this is only within a controller, so we
+        * don't need to wait for port 0, only for later ports.
+        */
+       if (!(ap->host->flags & ATA_HOST_PARALLEL_SCAN) && ap->port_no != 0)
+               async_synchronize_cookie(cookie);
+
+       /* probe */
+       if (ap->ops->error_handler) {
+               struct ata_eh_info *ehi = &ap->link.eh_info;
+               unsigned long flags;
+
+               ata_port_probe(ap);
+
+               /* kick EH for boot probing */
+               spin_lock_irqsave(ap->lock, flags);
+
+               ehi->probe_mask |= ATA_ALL_DEVICES;
+               ehi->action |= ATA_EH_RESET | ATA_EH_LPM;
+               ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
+
+               ap->pflags &= ~ATA_PFLAG_INITIALIZING;
+               ap->pflags |= ATA_PFLAG_LOADING;
+               ata_port_schedule_eh(ap);
+
+               spin_unlock_irqrestore(ap->lock, flags);
+
+               /* wait for EH to finish */
+               ata_port_wait_eh(ap);
+       } else {
+               DPRINTK("ata%u: bus probe begin\n", ap->print_id);
+               rc = ata_bus_probe(ap);
+               DPRINTK("ata%u: bus probe end\n", ap->print_id);
+
+               if (rc) {
+                       /* FIXME: do something useful here?
+                        * Current libata behavior will
+                        * tear down everything when
+                        * the module is removed
+                        * or the h/w is unplugged.
+                        */
+               }
+       }
+
+       /* in order to keep device order, we need to synchronize at this point */
+       async_synchronize_cookie(cookie);
+
+       ata_scsi_scan_host(ap, 1);
+
+}
 /**
  *     ata_host_register - register initialized ATA host
  *     @host: ATA host to register
@@ -5791,52 +6053,9 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
        DPRINTK("probe begin\n");
        for (i = 0; i < host->n_ports; i++) {
                struct ata_port *ap = host->ports[i];
-
-               /* probe */
-               if (ap->ops->error_handler) {
-                       struct ata_eh_info *ehi = &ap->link.eh_info;
-                       unsigned long flags;
-
-                       ata_port_probe(ap);
-
-                       /* kick EH for boot probing */
-                       spin_lock_irqsave(ap->lock, flags);
-
-                       ehi->probe_mask |= ATA_ALL_DEVICES;
-                       ehi->action |= ATA_EH_RESET | ATA_EH_LPM;
-                       ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
-
-                       ap->pflags &= ~ATA_PFLAG_INITIALIZING;
-                       ap->pflags |= ATA_PFLAG_LOADING;
-                       ata_port_schedule_eh(ap);
-
-                       spin_unlock_irqrestore(ap->lock, flags);
-
-                       /* wait for EH to finish */
-                       ata_port_wait_eh(ap);
-               } else {
-                       DPRINTK("ata%u: bus probe begin\n", ap->print_id);
-                       rc = ata_bus_probe(ap);
-                       DPRINTK("ata%u: bus probe end\n", ap->print_id);
-
-                       if (rc) {
-                               /* FIXME: do something useful here?
-                                * Current libata behavior will
-                                * tear down everything when
-                                * the module is removed
-                                * or the h/w is unplugged.
-                                */
-                       }
-               }
-       }
-
-       /* probes are done, now scan each port's disk(s) */
-       DPRINTK("host probe begin\n");
-       for (i = 0; i < host->n_ports; i++) {
-               struct ata_port *ap = host->ports[i];
-
-               ata_scsi_scan_host(ap, 1);
+               async_schedule(async_port_probe, ap);
        }
+       DPRINTK("probe end\n");
 
        return 0;
 }
@@ -5910,8 +6129,6 @@ int ata_host_activate(struct ata_host *host, int irq,
 static void ata_port_detach(struct ata_port *ap)
 {
        unsigned long flags;
-       struct ata_link *link;
-       struct ata_device *dev;
 
        if (!ap->ops->error_handler)
                goto skip_eh;
@@ -5919,28 +6136,15 @@ static void ata_port_detach(struct ata_port *ap)
        /* tell EH we're leaving & flush EH */
        spin_lock_irqsave(ap->lock, flags);
        ap->pflags |= ATA_PFLAG_UNLOADING;
+       ata_port_schedule_eh(ap);
        spin_unlock_irqrestore(ap->lock, flags);
 
+       /* wait till EH commits suicide */
        ata_port_wait_eh(ap);
 
-       /* EH is now guaranteed to see UNLOADING - EH context belongs
-        * to us.  Restore SControl and disable all existing devices.
-        */
-       __ata_port_for_each_link(link, ap) {
-               sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
-               ata_link_for_each_dev(dev, link)
-                       ata_dev_disable(dev);
-       }
+       /* it better be dead now */
+       WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
 
-       /* Final freeze & EH.  All in-flight commands are aborted.  EH
-        * will be skipped and retrials will be terminated with bad
-        * target.
-        */
-       spin_lock_irqsave(ap->lock, flags);
-       ata_port_freeze(ap);    /* won't be thawed */
-       spin_unlock_irqrestore(ap->lock, flags);
-
-       ata_port_wait_eh(ap);
        cancel_rearming_delayed_work(&ap->hotplug_task);
 
  skip_eh:
@@ -6391,7 +6595,8 @@ EXPORT_SYMBOL_GPL(ata_base_port_ops);
 EXPORT_SYMBOL_GPL(sata_port_ops);
 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
-EXPORT_SYMBOL_GPL(__ata_port_next_link);
+EXPORT_SYMBOL_GPL(ata_link_next);
+EXPORT_SYMBOL_GPL(ata_dev_next);
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_host_init);
 EXPORT_SYMBOL_GPL(ata_host_alloc);