1 files changed, 72 insertions, 24 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 88c242856dae..9fbf0595f3d4 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -164,6 +164,11 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 
+static bool ata_sstatus_online(u32 sstatus)
+{
+        return (sstatus & 0xf) == 0x3;
+}
+
 /**
  *      ata_link_next - link iteration helper
  *      @link: the previous link, NULL to start
@@ -1015,18 +1020,6 @@ static const char *sata_spd_string(unsigned int spd)
         return spd_str[spd - 1];
 }
 
-void ata_dev_disable(struct ata_device *dev)
-{
-        if (ata_dev_enabled(dev)) {
-                if (ata_msg_drv(dev->link->ap))
-                        ata_dev_printk(dev, KERN_WARNING, "disabled\n");
-                ata_acpi_on_disable(dev);
-                ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
-                                             ATA_DNXFER_QUIET);
-                dev->class++;
-        }
-}
-
 static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
 {
         struct ata_link *link = dev->link;
@@ -2239,6 +2232,40 @@ retry:
         return rc;
 }
 
+static int ata_do_link_spd_horkage(struct ata_device *dev)
+{
+        struct ata_link *plink = ata_dev_phys_link(dev);
+        u32 target, target_limit;
+
+        if (!sata_scr_valid(plink))
+                return 0;
+
+        if (dev->horkage & ATA_HORKAGE_1_5_GBPS)
+                target = 1;
+        else
+                return 0;
+
+        target_limit = (1 << target) - 1;
+
+        /* if already on stricter limit, no need to push further */
+        if (plink->sata_spd_limit <= target_limit)
+                return 0;
+
+        plink->sata_spd_limit = target_limit;
+
+        /* Request another EH round by returning -EAGAIN if link is
+         * going faster than the target speed.  Forward progress is
+         * guaranteed by setting sata_spd_limit to target_limit above.
+         */
+        if (plink->sata_spd > target) {
+                ata_dev_printk(dev, KERN_INFO,
+                               "applying link speed limit horkage to %s\n",
+                               sata_spd_string(target));
+                return -EAGAIN;
+        }
+        return 0;
+}
+
 static inline u8 ata_dev_knobble(struct ata_device *dev)
 {
         struct ata_port *ap = dev->link->ap;
@@ -2329,6 +2356,10 @@ int ata_dev_configure(struct ata_device *dev)
                 return 0;
         }
 
+        rc = ata_do_link_spd_horkage(dev);
+        if (rc)
+                return rc;
+
         /* let ACPI work its magic */
         rc = ata_acpi_on_devcfg(dev);
         if (rc)
@@ -2784,7 +2815,7 @@ int ata_bus_probe(struct ata_port *ap)
                         /* This is the last chance, better to slow
                          * down than lose it.
                          */
-                        sata_down_spd_limit(&ap->link);
+                        sata_down_spd_limit(&ap->link, 0);
                         ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
                 }
         }
@@ -2880,21 +2911,27 @@ void ata_port_disable(struct ata_port *ap)
 /**
  *      sata_down_spd_limit - adjust SATA spd limit downward
  *      @link: Link to adjust SATA spd limit for
+ *      @spd_limit: Additional limit
  *
  *      Adjust SATA spd limit of @link downward.  Note that this
  *      function only adjusts the limit.  The change must be applied
  *      using sata_set_spd().
  *
+ *      If @spd_limit is non-zero, the speed is limited to equal to or
+ *      lower than @spd_limit if such speed is supported.  If
+ *      @spd_limit is slower than any supported speed, only the lowest
+ *      supported speed is allowed.
+ *
  *      LOCKING:
  *      Inherited from caller.
  *
  *      RETURNS:
  *      0 on success, negative errno on failure
  */
-int sata_down_spd_limit(struct ata_link *link)
+int sata_down_spd_limit(struct ata_link *link, u32 spd_limit)
 {
         u32 sstatus, spd, mask;
-        int rc, highbit;
+        int rc, bit;
 
         if (!sata_scr_valid(link))
                 return -EOPNOTSUPP;
@@ -2903,7 +2940,7 @@ int sata_down_spd_limit(struct ata_link *link)
          * If not, use cached value in link->sata_spd.
          */
         rc = sata_scr_read(link, SCR_STATUS, &sstatus);
-        if (rc == 0)
+        if (rc == 0 && ata_sstatus_online(sstatus))
                 spd = (sstatus >> 4) & 0xf;
         else
                 spd = link->sata_spd;
@@ -2913,8 +2950,8 @@ int sata_down_spd_limit(struct ata_link *link)
                 return -EINVAL;
 
         /* unconditionally mask off the highest bit */
-        highbit = fls(mask) - 1;
-        mask &= ~(1 << highbit);
+        bit = fls(mask) - 1;
+        mask &= ~(1 << bit);
 
         /* Mask off all speeds higher than or equal to the current
          * one.  Force 1.5Gbps if current SPD is not available.
@@ -2928,6 +2965,15 @@ int sata_down_spd_limit(struct ata_link *link)
         if (!mask)
                 return -EINVAL;
 
+        if (spd_limit) {
+                if (mask & ((1 << spd_limit) - 1))
+                        mask &= (1 << spd_limit) - 1;
+                else {
+                        bit = ffs(mask) - 1;
+                        mask = 1 << bit;
+                }
+        }
+
         link->sata_spd_limit = mask;
 
         ata_link_printk(link, KERN_WARNING, "limiting SATA link speed to %s\n",
@@ -4215,6 +4261,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
         /* Devices that do not need bridging limits applied */
         { "MTRON MSP-SATA*",            NULL,   ATA_HORKAGE_BRIDGE_OK, },
 
+        /* Devices which aren't very happy with higher link speeds */
+        { "WD My Book",                 NULL,   ATA_HORKAGE_1_5_GBPS, },
+
         /* End Marker */
         { }
 };
@@ -4709,8 +4758,7 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 
 /**
  *      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
+ *      @ap: target port
  *
  *      LOCKING:
  *      None.
@@ -5175,7 +5223,7 @@ bool ata_phys_link_online(struct ata_link *link)
         u32 sstatus;
 
         if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
-            (sstatus & 0xf) == 0x3)
+            ata_sstatus_online(sstatus))
                 return true;
         return false;
 }
@@ -5199,7 +5247,7 @@ bool ata_phys_link_offline(struct ata_link *link)
         u32 sstatus;
 
         if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
-            (sstatus & 0xf) != 0x3)
+            !ata_sstatus_online(sstatus))
                 return true;
         return false;
 }
@@ -5412,8 +5460,8 @@ void ata_dev_init(struct ata_device *dev)
         dev->horkage = 0;
         spin_unlock_irqrestore(ap->lock, flags);
 
-        memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
-               sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
+        memset((void *)dev + ATA_DEVICE_CLEAR_BEGIN, 0,
+               ATA_DEVICE_CLEAR_END - ATA_DEVICE_CLEAR_BEGIN);
         dev->pio_mask = UINT_MAX;
         dev->mwdma_mask = UINT_MAX;
         dev->udma_mask = UINT_MAX;