Merge branch 'v3.10/topic/gator' into linux-linaro-lsk-v3.10

[firefly-linux-kernel-4.4.55.git] / drivers / ata / libata-core.c

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 9cf616b5210bcb7b866284caed4f66fa52971a4b..ca7c23d58a038c17c3799c3b75e2156e04024d8a 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4758,6 +4758,10 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
  *     ata_qc_new - Request an available ATA command, for queueing
  *     @ap: target port
  *
+ *     Some ATA host controllers may implement a queue depth which is less
+ *     than ATA_MAX_QUEUE. So we shouldn't allocate a tag which is beyond
+ *     the hardware limitation.
+ *
  *     LOCKING:
  *     None.
  */
@@ -4765,14 +4769,15 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
 {
        struct ata_queued_cmd *qc = NULL;
+       unsigned int max_queue = ap->host->n_tags;
        unsigned int i, tag;
 
        /* no command while frozen */
        if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
                return NULL;
 
-       for (i = 0; i < ATA_MAX_QUEUE; i++) {
-               tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE;
+       for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
+               tag = tag < max_queue ? tag : 0;
 
                /* the last tag is reserved for internal command. */
                if (tag == ATA_TAG_INTERNAL)
@@ -6073,6 +6078,7 @@ void ata_host_init(struct ata_host *host, struct device *dev,
 {
        spin_lock_init(&host->lock);
        mutex_init(&host->eh_mutex);
+       host->n_tags = ATA_MAX_QUEUE - 1;
        host->dev = dev;
        host->ops = ops;
 }
@@ -6154,6 +6160,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 {
        int i, rc;
 
+       host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE - 1);
+
        /* host must have been started */
        if (!(host->flags & ATA_HOST_STARTED)) {
                dev_err(host->dev, "BUG: trying to register unstarted host\n");
@@ -6300,6 +6308,8 @@ 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;
@@ -6319,6 +6329,13 @@ static void ata_port_detach(struct ata_port *ap)
        cancel_delayed_work_sync(&ap->hotplug_task);
 
  skip_eh:
+       /* clean up zpodd on port removal */
+       ata_for_each_link(link, ap, HOST_FIRST) {
+               ata_for_each_dev(dev, link, ALL) {
+                       if (zpodd_dev_enabled(dev))
+                               zpodd_exit(dev);
+               }
+       }
        if (ap->pmp_link) {
                int i;
                for (i = 0; i < SATA_PMP_MAX_PORTS; i++)