]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blobdiff - drivers/scsi/libsas/sas_ata.c
[SCSI] libsas: execute transport link resets with libata-eh via host workqueue
[mirror_ubuntu-bionic-kernel.git] / drivers / scsi / libsas / sas_ata.c
index db9238f2ecb8b7596dda9c2d4132000af0910bd7..03930a04a679e88679dc037b055027410a4dca63 100644 (file)
@@ -93,22 +93,47 @@ static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
 static void sas_ata_task_done(struct sas_task *task)
 {
        struct ata_queued_cmd *qc = task->uldd_task;
-       struct domain_device *dev;
+       struct domain_device *dev = task->dev;
        struct task_status_struct *stat = &task->task_status;
        struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
-       struct sas_ha_struct *sas_ha;
+       struct sas_ha_struct *sas_ha = dev->port->ha;
        enum ata_completion_errors ac;
        unsigned long flags;
        struct ata_link *link;
+       struct ata_port *ap;
+
+       spin_lock_irqsave(&dev->done_lock, flags);
+       if (test_bit(SAS_HA_FROZEN, &sas_ha->state))
+               task = NULL;
+       else if (qc && qc->scsicmd)
+               ASSIGN_SAS_TASK(qc->scsicmd, NULL);
+       spin_unlock_irqrestore(&dev->done_lock, flags);
+
+       /* check if libsas-eh got to the task before us */
+       if (unlikely(!task))
+               return;
 
        if (!qc)
                goto qc_already_gone;
 
-       dev = qc->ap->private_data;
-       sas_ha = dev->port->ha;
-       link = &dev->sata_dev.ap->link;
+       ap = qc->ap;
+       link = &ap->link;
+
+       spin_lock_irqsave(ap->lock, flags);
+       /* check if we lost the race with libata/sas_ata_post_internal() */
+       if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) {
+               spin_unlock_irqrestore(ap->lock, flags);
+               if (qc->scsicmd)
+                       goto qc_already_gone;
+               else {
+                       /* if eh is not involved and the port is frozen then the
+                        * ata internal abort process has taken responsibility
+                        * for this sas_task
+                        */
+                       return;
+               }
+       }
 
-       spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
        if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_STAT_GOOD ||
            ((stat->stat == SAM_STAT_CHECK_CONDITION &&
              dev->sata_dev.command_set == ATAPI_COMMAND_SET))) {
@@ -121,10 +146,6 @@ static void sas_ata_task_done(struct sas_task *task)
                        if (unlikely(link->eh_info.err_mask))
                                qc->flags |= ATA_QCFLAG_FAILED;
                }
-
-               dev->sata_dev.sstatus = resp->sstatus;
-               dev->sata_dev.serror = resp->serror;
-               dev->sata_dev.scontrol = resp->scontrol;
        } else {
                ac = sas_to_ata_err(stat);
                if (ac) {
@@ -144,24 +165,8 @@ static void sas_ata_task_done(struct sas_task *task)
        }
 
        qc->lldd_task = NULL;
-       if (qc->scsicmd)
-               ASSIGN_SAS_TASK(qc->scsicmd, NULL);
        ata_qc_complete(qc);
-       spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
-
-       /*
-        * If the sas_task has an ata qc, a scsi_cmnd and the aborted
-        * flag is set, then we must have come in via the libsas EH
-        * functions.  When we exit this function, we need to put the
-        * scsi_cmnd on the list of finished errors.  The ata_qc_complete
-        * call cleans up the libata side of things but we're protected
-        * from the scsi_cmnd going away because the scsi_cmnd is owned
-        * by the EH, making libata's call to scsi_done a NOP.
-        */
-       spin_lock_irqsave(&task->task_state_lock, flags);
-       if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
-               scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
-       spin_unlock_irqrestore(&task->task_state_lock, flags);
+       spin_unlock_irqrestore(ap->lock, flags);
 
 qc_already_gone:
        list_del_init(&task->list);
@@ -170,23 +175,30 @@ qc_already_gone:
 
 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
 {
-       int res;
+       unsigned long flags;
        struct sas_task *task;
-       struct domain_device *dev = qc->ap->private_data;
+       struct scatterlist *sg;
+       int ret = AC_ERR_SYSTEM;
+       unsigned int si, xfer = 0;
+       struct ata_port *ap = qc->ap;
+       struct domain_device *dev = ap->private_data;
        struct sas_ha_struct *sas_ha = dev->port->ha;
        struct Scsi_Host *host = sas_ha->core.shost;
        struct sas_internal *i = to_sas_internal(host->transportt);
-       struct scatterlist *sg;
-       unsigned int xfer = 0;
-       unsigned int si;
+
+       /* TODO: audit callers to ensure they are ready for qc_issue to
+        * unconditionally re-enable interrupts
+        */
+       local_irq_save(flags);
+       spin_unlock(ap->lock);
 
        /* If the device fell off, no sense in issuing commands */
-       if (dev->gone)
-               return AC_ERR_SYSTEM;
+       if (test_bit(SAS_DEV_GONE, &dev->state))
+               goto out;
 
        task = sas_alloc_task(GFP_ATOMIC);
        if (!task)
-               return AC_ERR_SYSTEM;
+               goto out;
        task->dev = dev;
        task->task_proto = SAS_PROTOCOL_STP;
        task->task_done = sas_ata_task_done;
@@ -231,21 +243,24 @@ static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
                ASSIGN_SAS_TASK(qc->scsicmd, task);
 
        if (sas_ha->lldd_max_execute_num < 2)
-               res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
+               ret = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
        else
-               res = sas_queue_up(task);
+               ret = sas_queue_up(task);
 
        /* Examine */
-       if (res) {
-               SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
+       if (ret) {
+               SAS_DPRINTK("lldd_execute_task returned: %d\n", ret);
 
                if (qc->scsicmd)
                        ASSIGN_SAS_TASK(qc->scsicmd, NULL);
                sas_free_task(task);
-               return AC_ERR_SYSTEM;
+               ret = AC_ERR_SYSTEM;
        }
 
-       return 0;
+ out:
+       spin_lock(ap->lock);
+       local_irq_restore(flags);
+       return ret;
 }
 
 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
@@ -333,6 +348,54 @@ static int sas_ata_soft_reset(struct ata_link *link, unsigned int *class,
        return ret;
 }
 
+/*
+ * notify the lldd to forget the sas_task for this internal ata command
+ * that bypasses scsi-eh
+ */
+static void sas_ata_internal_abort(struct sas_task *task)
+{
+       struct sas_internal *si =
+               to_sas_internal(task->dev->port->ha->core.shost->transportt);
+       unsigned long flags;
+       int res;
+
+       spin_lock_irqsave(&task->task_state_lock, flags);
+       if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
+           task->task_state_flags & SAS_TASK_STATE_DONE) {
+               spin_unlock_irqrestore(&task->task_state_lock, flags);
+               SAS_DPRINTK("%s: Task %p already finished.\n", __func__,
+                           task);
+               goto out;
+       }
+       task->task_state_flags |= SAS_TASK_STATE_ABORTED;
+       spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+       res = si->dft->lldd_abort_task(task);
+
+       spin_lock_irqsave(&task->task_state_lock, flags);
+       if (task->task_state_flags & SAS_TASK_STATE_DONE ||
+           res == TMF_RESP_FUNC_COMPLETE) {
+               spin_unlock_irqrestore(&task->task_state_lock, flags);
+               goto out;
+       }
+
+       /* XXX we are not prepared to deal with ->lldd_abort_task()
+        * failures.  TODO: lldds need to unconditionally forget about
+        * aborted ata tasks, otherwise we (likely) leak the sas task
+        * here
+        */
+       SAS_DPRINTK("%s: Task %p leaked.\n", __func__, task);
+
+       if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
+               task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
+       spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+       return;
+ out:
+       list_del_init(&task->list);
+       sas_free_task(task);
+}
+
 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
 {
        if (qc->flags & ATA_QCFLAG_FAILED)
@@ -340,27 +403,34 @@ static void sas_ata_post_internal(struct ata_queued_cmd *qc)
 
        if (qc->err_mask) {
                /*
-                * Find the sas_task and kill it.  By this point,
-                * libata has decided to kill the qc, so we needn't
-                * bother with sas_ata_task_done.  But we still
-                * ought to abort the task.
+                * Find the sas_task and kill it.  By this point, libata
+                * has decided to kill the qc and has frozen the port.
+                * In this state sas_ata_task_done() will no longer free
+                * the sas_task, so we need to notify the lldd (via
+                * ->lldd_abort_task) that the task is dead and free it
+                *  ourselves.
                 */
                struct sas_task *task = qc->lldd_task;
-               unsigned long flags;
 
                qc->lldd_task = NULL;
-               if (task) {
-                       /* Should this be a AT(API) device reset? */
-                       spin_lock_irqsave(&task->task_state_lock, flags);
-                       task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
-                       spin_unlock_irqrestore(&task->task_state_lock, flags);
-
-                       task->uldd_task = NULL;
-                       __sas_task_abort(task);
-               }
+               if (!task)
+                       return;
+               task->uldd_task = NULL;
+               sas_ata_internal_abort(task);
        }
 }
 
+
+static void sas_ata_set_dmamode(struct ata_port *ap, struct ata_device *ata_dev)
+{
+       struct domain_device *dev = ap->private_data;
+       struct sas_internal *i =
+               to_sas_internal(dev->port->ha->core.shost->transportt);
+
+       if (i->dft->lldd_ata_set_dmamode)
+               i->dft->lldd_ata_set_dmamode(dev);
+}
+
 static struct ata_port_operations sas_sata_ops = {
        .prereset               = ata_std_prereset,
        .softreset              = sas_ata_soft_reset,
@@ -374,6 +444,7 @@ static struct ata_port_operations sas_sata_ops = {
        .qc_fill_rtf            = sas_ata_qc_fill_rtf,
        .port_start             = ata_sas_port_start,
        .port_stop              = ata_sas_port_stop,
+       .set_dmamode            = sas_ata_set_dmamode,
 };
 
 static struct ata_port_info sata_port_info = {
@@ -436,163 +507,6 @@ void sas_ata_task_abort(struct sas_task *task)
        complete(waiting);
 }
 
-static void sas_task_timedout(unsigned long _task)
-{
-       struct sas_task *task = (void *) _task;
-       unsigned long flags;
-
-       spin_lock_irqsave(&task->task_state_lock, flags);
-       if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
-               task->task_state_flags |= SAS_TASK_STATE_ABORTED;
-       spin_unlock_irqrestore(&task->task_state_lock, flags);
-
-       complete(&task->completion);
-}
-
-static void sas_disc_task_done(struct sas_task *task)
-{
-       if (!del_timer(&task->timer))
-               return;
-       complete(&task->completion);
-}
-
-#define SAS_DEV_TIMEOUT 10
-
-/**
- * sas_execute_task -- Basic task processing for discovery
- * @task: the task to be executed
- * @buffer: pointer to buffer to do I/O
- * @size: size of @buffer
- * @dma_dir: DMA direction.  DMA_xxx
- */
-static int sas_execute_task(struct sas_task *task, void *buffer, int size,
-                           enum dma_data_direction dma_dir)
-{
-       int res = 0;
-       struct scatterlist *scatter = NULL;
-       struct task_status_struct *ts = &task->task_status;
-       int num_scatter = 0;
-       int retries = 0;
-       struct sas_internal *i =
-               to_sas_internal(task->dev->port->ha->core.shost->transportt);
-
-       if (dma_dir != DMA_NONE) {
-               scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
-               if (!scatter)
-                       goto out;
-
-               sg_init_one(scatter, buffer, size);
-               num_scatter = 1;
-       }
-
-       task->task_proto = task->dev->tproto;
-       task->scatter = scatter;
-       task->num_scatter = num_scatter;
-       task->total_xfer_len = size;
-       task->data_dir = dma_dir;
-       task->task_done = sas_disc_task_done;
-       if (dma_dir != DMA_NONE &&
-           sas_protocol_ata(task->task_proto)) {
-               task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
-                                              task->scatter,
-                                              task->num_scatter,
-                                              task->data_dir);
-       }
-
-       for (retries = 0; retries < 5; retries++) {
-               task->task_state_flags = SAS_TASK_STATE_PENDING;
-               init_completion(&task->completion);
-
-               task->timer.data = (unsigned long) task;
-               task->timer.function = sas_task_timedout;
-               task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
-               add_timer(&task->timer);
-
-               res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
-               if (res) {
-                       del_timer(&task->timer);
-                       SAS_DPRINTK("executing SAS discovery task failed:%d\n",
-                                   res);
-                       goto ex_err;
-               }
-               wait_for_completion(&task->completion);
-               res = -ECOMM;
-               if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
-                       int res2;
-                       SAS_DPRINTK("task aborted, flags:0x%x\n",
-                                   task->task_state_flags);
-                       res2 = i->dft->lldd_abort_task(task);
-                       SAS_DPRINTK("came back from abort task\n");
-                       if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
-                               if (res2 == TMF_RESP_FUNC_COMPLETE)
-                                       continue; /* Retry the task */
-                               else
-                                       goto ex_err;
-                       }
-               }
-               if (task->task_status.stat == SAM_STAT_BUSY ||
-                          task->task_status.stat == SAM_STAT_TASK_SET_FULL ||
-                          task->task_status.stat == SAS_QUEUE_FULL) {
-                       SAS_DPRINTK("task: q busy, sleeping...\n");
-                       schedule_timeout_interruptible(HZ);
-               } else if (task->task_status.stat == SAM_STAT_CHECK_CONDITION) {
-                       struct scsi_sense_hdr shdr;
-
-                       if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
-                                                 &shdr)) {
-                               SAS_DPRINTK("couldn't normalize sense\n");
-                               continue;
-                       }
-                       if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
-                           (shdr.sense_key == 2 && shdr.asc == 4 &&
-                            shdr.ascq == 1)) {
-                               SAS_DPRINTK("device %016llx LUN: %016llx "
-                                           "powering up or not ready yet, "
-                                           "sleeping...\n",
-                                           SAS_ADDR(task->dev->sas_addr),
-                                           SAS_ADDR(task->ssp_task.LUN));
-
-                               schedule_timeout_interruptible(5*HZ);
-                       } else if (shdr.sense_key == 1) {
-                               res = 0;
-                               break;
-                       } else if (shdr.sense_key == 5) {
-                               break;
-                       } else {
-                               SAS_DPRINTK("dev %016llx LUN: %016llx "
-                                           "sense key:0x%x ASC:0x%x ASCQ:0x%x"
-                                           "\n",
-                                           SAS_ADDR(task->dev->sas_addr),
-                                           SAS_ADDR(task->ssp_task.LUN),
-                                           shdr.sense_key,
-                                           shdr.asc, shdr.ascq);
-                       }
-               } else if (task->task_status.resp != SAS_TASK_COMPLETE ||
-                          task->task_status.stat != SAM_STAT_GOOD) {
-                       SAS_DPRINTK("task finished with resp:0x%x, "
-                                   "stat:0x%x\n",
-                                   task->task_status.resp,
-                                   task->task_status.stat);
-                       goto ex_err;
-               } else {
-                       res = 0;
-                       break;
-               }
-       }
-ex_err:
-       if (dma_dir != DMA_NONE) {
-               if (sas_protocol_ata(task->task_proto))
-                       dma_unmap_sg(task->dev->port->ha->dev,
-                                    task->scatter, task->num_scatter,
-                                    task->data_dir);
-               kfree(scatter);
-       }
-out:
-       return res;
-}
-
-/* ---------- SATA ---------- */
-
 static void sas_get_ata_command_set(struct domain_device *dev)
 {
        struct dev_to_host_fis *fis =
@@ -636,169 +550,75 @@ static void sas_get_ata_command_set(struct domain_device *dev)
                dev->sata_dev.command_set = ATAPI_COMMAND_SET;
 }
 
-/**
- * sas_issue_ata_cmd -- Basic SATA command processing for discovery
- * @dev: the device to send the command to
- * @command: the command register
- * @features: the features register
- * @buffer: pointer to buffer to do I/O
- * @size: size of @buffer
- * @dma_dir: DMA direction.  DMA_xxx
- */
-static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
-                            u8 features, void *buffer, int size,
-                            enum dma_data_direction dma_dir)
+void sas_probe_sata(struct work_struct *work)
 {
-       int res = 0;
-       struct sas_task *task;
-       struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
-               &dev->frame_rcvd[0];
-
-       res = -ENOMEM;
-       task = sas_alloc_task(GFP_KERNEL);
-       if (!task)
-               goto out;
-
-       task->dev = dev;
-
-       task->ata_task.fis.fis_type = 0x27;
-       task->ata_task.fis.command = command;
-       task->ata_task.fis.features = features;
-       task->ata_task.fis.device = d2h_fis->device;
-       task->ata_task.retry_count = 1;
-
-       res = sas_execute_task(task, buffer, size, dma_dir);
-
-       sas_free_task(task);
-out:
-       return res;
-}
-
-#define ATA_IDENTIFY_DEV         0xEC
-#define ATA_IDENTIFY_PACKET_DEV  0xA1
-#define ATA_SET_FEATURES         0xEF
-#define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
-
-/**
- * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
- * @dev: STP/SATA device of interest (ATA/ATAPI)
- *
- * The LLDD has already been notified of this device, so that we can
- * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
- * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
- * performance for this device.
- */
-static int sas_discover_sata_dev(struct domain_device *dev)
-{
-       int     res;
-       __le16  *identify_x;
-       u8      command;
-
-       identify_x = kzalloc(512, GFP_KERNEL);
-       if (!identify_x)
-               return -ENOMEM;
-
-       if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
-               dev->sata_dev.identify_device = identify_x;
-               command = ATA_IDENTIFY_DEV;
-       } else {
-               dev->sata_dev.identify_packet_device = identify_x;
-               command = ATA_IDENTIFY_PACKET_DEV;
+       struct domain_device *dev, *n;
+       struct sas_discovery_event *ev =
+               container_of(work, struct sas_discovery_event, work);
+       struct asd_sas_port *port = ev->port;
+
+       clear_bit(DISCE_PROBE, &port->disc.pending);
+
+       list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+               int err;
+
+               spin_lock_irq(&port->dev_list_lock);
+               list_add_tail(&dev->dev_list_node, &port->dev_list);
+               spin_unlock_irq(&port->dev_list_lock);
+
+               err = sas_rphy_add(dev->rphy);
+
+               if (err) {
+                       SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
+                                   __func__, dev->parent ? "exp-attached" :
+                                                           "direct-attached",
+                                   SAS_ADDR(dev->sas_addr), err);
+                       sas_unregister_dev(port, dev);
+               } else
+                       list_del_init(&dev->disco_list_node);
        }
-
-       res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
-                               DMA_FROM_DEVICE);
-       if (res)
-               goto out_err;
-
-       /* lives on the media? */
-       if (le16_to_cpu(identify_x[0]) & 4) {
-               /* incomplete response */
-               SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
-                           "dev %llx\n", SAS_ADDR(dev->sas_addr));
-               if (!(identify_x[83] & cpu_to_le16(1<<6)))
-                       goto cont1;
-               res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
-                                       ATA_FEATURE_PUP_STBY_SPIN_UP,
-                                       NULL, 0, DMA_NONE);
-               if (res)
-                       goto cont1;
-
-               schedule_timeout_interruptible(5*HZ); /* More time? */
-               res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
-                                       DMA_FROM_DEVICE);
-               if (res)
-                       goto out_err;
-       }
-cont1:
-       /* XXX Hint: register this SATA device with SATL.
-          When this returns, dev->sata_dev->lu is alive and
-          present.
-       sas_satl_register_dev(dev);
-       */
-
-       sas_fill_in_rphy(dev, dev->rphy);
-
-       return 0;
-out_err:
-       dev->sata_dev.identify_packet_device = NULL;
-       dev->sata_dev.identify_device = NULL;
-       kfree(identify_x);
-       return res;
-}
-
-static int sas_discover_sata_pm(struct domain_device *dev)
-{
-       return -ENODEV;
 }
 
 /**
  * sas_discover_sata -- discover an STP/SATA domain device
  * @dev: pointer to struct domain_device of interest
  *
- * First we notify the LLDD of this device, so we can send frames to
- * it.  Then depending on the type of device we call the appropriate
- * discover functions.  Once device discover is done, we notify the
- * LLDD so that it can fine-tune its parameters for the device, by
- * removing it and then adding it.  That is, the second time around,
- * the driver would have certain fields, that it is looking at, set.
- * Finally we initialize the kobj so that the device can be added to
- * the system at registration time.  Devices directly attached to a HA
- * port, have no parents.  All other devices do, and should have their
- * "parent" pointer set appropriately before calling this function.
+ * Devices directly attached to a HA port, have no parents.  All other
+ * devices do, and should have their "parent" pointer set appropriately
+ * before calling this function.
  */
 int sas_discover_sata(struct domain_device *dev)
 {
        int res;
 
+       if (dev->dev_type == SATA_PM)
+               return -ENODEV;
+
        sas_get_ata_command_set(dev);
+       sas_fill_in_rphy(dev, dev->rphy);
 
        res = sas_notify_lldd_dev_found(dev);
        if (res)
                return res;
 
-       switch (dev->dev_type) {
-       case SATA_DEV:
-               res = sas_discover_sata_dev(dev);
-               break;
-       case SATA_PM:
-               res = sas_discover_sata_pm(dev);
-               break;
-       default:
-               break;
-       }
-       sas_notify_lldd_dev_gone(dev);
-       if (!res) {
-               sas_notify_lldd_dev_found(dev);
-               res = sas_rphy_add(dev->rphy);
-       }
-
-       return res;
+       sas_discover_event(dev->port, DISCE_PROBE);
+       return 0;
 }
 
 void sas_ata_strategy_handler(struct Scsi_Host *shost)
 {
        struct scsi_device *sdev;
+       struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
+
+       /* it's ok to defer revalidation events during ata eh, these
+        * disks are in one of three states:
+        * 1/ present for initial domain discovery, and these
+        *    resets will cause bcn flutters
+        * 2/ hot removed, we'll discover that after eh fails
+        * 3/ hot added after initial discovery, lost the race, and need
+        *    to catch the next train.
+        */
+       sas_disable_revalidation(sas_ha);
 
        shost_for_each_device(sdev, shost) {
                struct domain_device *ddev = sdev_to_domain_dev(sdev);
@@ -810,22 +630,8 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
                ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
                ata_scsi_port_error_handler(shost, ap);
        }
-}
-
-int sas_ata_timed_out(struct scsi_cmnd *cmd, struct sas_task *task,
-                     enum blk_eh_timer_return *rtn)
-{
-       struct domain_device *ddev = cmd_to_domain_dev(cmd);
-
-       if (!dev_is_sata(ddev) || task)
-               return 0;
 
-       /* we're a sata device with no task, so this must be a libata
-        * eh timeout.  Ideally should hook into libata timeout
-        * handling, but there's no point, it just wants to activate
-        * the eh thread */
-       *rtn = BLK_EH_NOT_HANDLED;
-       return 1;
+       sas_enable_revalidation(sas_ha);
 }
 
 int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
@@ -873,3 +679,33 @@ int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 
        return rtn;
 }
+
+void sas_ata_schedule_reset(struct domain_device *dev)
+{
+       struct ata_eh_info *ehi;
+       struct ata_port *ap;
+       unsigned long flags;
+
+       if (!dev_is_sata(dev))
+               return;
+
+       ap = dev->sata_dev.ap;
+       ehi = &ap->link.eh_info;
+
+       spin_lock_irqsave(ap->lock, flags);
+       ehi->err_mask |= AC_ERR_TIMEOUT;
+       ehi->action |= ATA_EH_RESET;
+       ata_port_schedule_eh(ap);
+       spin_unlock_irqrestore(ap->lock, flags);
+}
+
+void sas_ata_wait_eh(struct domain_device *dev)
+{
+       struct ata_port *ap;
+
+       if (!dev_is_sata(dev))
+               return;
+
+       ap = dev->sata_dev.ap;
+       ata_port_wait_eh(ap);
+}