1 files changed, 113 insertions, 94 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 62e033146bed..7894d83ea1eb 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1308,12 +1308,7 @@ static void ata_eh_analyze_serror(struct ata_link *link)
         unsigned int err_mask = 0, action = 0;
         u32 hotplug_mask;
 
-        if (serror & SERR_PERSISTENT) {
-                err_mask |= AC_ERR_ATA_BUS;
-                action |= ATA_EH_RESET;
-        }
-        if (serror &
-            (SERR_DATA_RECOVERED | SERR_COMM_RECOVERED | SERR_DATA)) {
+        if (serror & (SERR_PERSISTENT | SERR_DATA)) {
                 err_mask |= AC_ERR_ATA_BUS;
                 action |= ATA_EH_RESET;
         }
@@ -2047,19 +2042,11 @@ static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
                         unsigned int *classes, unsigned long deadline)
 {
         struct ata_device *dev;
-        int rc;
 
         ata_link_for_each_dev(dev, link)
                 classes[dev->devno] = ATA_DEV_UNKNOWN;
 
-        rc = reset(link, classes, deadline);
-
-        /* convert all ATA_DEV_UNKNOWN to ATA_DEV_NONE */
-        ata_link_for_each_dev(dev, link)
-                if (classes[dev->devno] == ATA_DEV_UNKNOWN)
-                        classes[dev->devno] = ATA_DEV_NONE;
-
-        return rc;
+        return reset(link, classes, deadline);
 }
 
 static int ata_eh_followup_srst_needed(struct ata_link *link,
@@ -2096,9 +2083,11 @@ int ata_eh_reset(struct ata_link *link, int classify,
         ata_reset_fn_t reset;
         unsigned long flags;
         u32 sstatus;
-        int rc;
+        int nr_known, rc;
 
-        /* about to reset */
+        /*
+         * Prepare to reset
+         */
         spin_lock_irqsave(ap->lock, flags);
         ap->pflags |= ATA_PFLAG_RESETTING;
         spin_unlock_irqrestore(ap->lock, flags);
@@ -2124,16 +2113,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
                         ap->ops->set_piomode(ap, dev);
         }
 
-        if (!softreset && !hardreset) {
-                if (verbose)
-                        ata_link_printk(link, KERN_INFO, "no reset method "
-                                        "available, skipping reset\n");
-                if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
-                        lflags |= ATA_LFLAG_ASSUME_ATA;
-                goto done;
-        }
-
         /* prefer hardreset */
+        reset = NULL;
         ehc->i.action &= ~ATA_EH_RESET;
         if (hardreset) {
                 reset = hardreset;
@@ -2141,11 +2122,6 @@ int ata_eh_reset(struct ata_link *link, int classify,
         } else if (softreset) {
                 reset = softreset;
                 ehc->i.action = ATA_EH_SOFTRESET;
-        } else {
-                ata_link_printk(link, KERN_ERR, "BUG: no reset method, "
-                                "please report to linux-ide@vger.kernel.org\n");
-                dump_stack();
-                return -EINVAL;
         }
 
         if (prereset) {
@@ -2165,55 +2141,71 @@ int ata_eh_reset(struct ata_link *link, int classify,
                                         "prereset failed (errno=%d)\n", rc);
                         goto out;
                 }
-        }
 
-        /* prereset() might have cleared ATA_EH_RESET */
-        if (!(ehc->i.action & ATA_EH_RESET)) {
-                /* prereset told us not to reset, bang classes and return */
-                ata_link_for_each_dev(dev, link)
-                        classes[dev->devno] = ATA_DEV_NONE;
-                rc = 0;
-                goto out;
+                /* prereset() might have cleared ATA_EH_RESET.  If so,
+                 * bang classes and return.
+                 */
+                if (reset && !(ehc->i.action & ATA_EH_RESET)) {
+                        ata_link_for_each_dev(dev, link)
+                                classes[dev->devno] = ATA_DEV_NONE;
+                        rc = 0;
+                        goto out;
+                }
         }
 
  retry:
+        /*
+         * Perform reset
+         */
+        if (ata_is_host_link(link))
+                ata_eh_freeze_port(ap);
+
         deadline = jiffies + ata_eh_reset_timeouts[try++];
 
-        /* shut up during boot probing */
-        if (verbose)
-                ata_link_printk(link, KERN_INFO, "%s resetting link\n",
-                                reset == softreset ? "soft" : "hard");
+        if (reset) {
+                if (verbose)
+                        ata_link_printk(link, KERN_INFO, "%s resetting link\n",
+                                        reset == softreset ? "soft" : "hard");
 
-        /* mark that this EH session started with reset */
-        if (reset == hardreset)
-                ehc->i.flags |= ATA_EHI_DID_HARDRESET;
-        else
-                ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
+                /* mark that this EH session started with reset */
+                if (reset == hardreset)
+                        ehc->i.flags |= ATA_EHI_DID_HARDRESET;
+                else
+                        ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
 
-        rc = ata_do_reset(link, reset, classes, deadline);
+                rc = ata_do_reset(link, reset, classes, deadline);
 
-        if (reset == hardreset &&
-            ata_eh_followup_srst_needed(link, rc, classify, classes)) {
-                /* okay, let's do follow-up softreset */
-                reset = softreset;
+                if (reset == hardreset &&
+                    ata_eh_followup_srst_needed(link, rc, classify, classes)) {
+                        /* okay, let's do follow-up softreset */
+                        reset = softreset;
 
-                if (!reset) {
-                        ata_link_printk(link, KERN_ERR,
-                                        "follow-up softreset required "
-                                        "but no softreset avaliable\n");
-                        rc = -EINVAL;
-                        goto fail;
+                        if (!reset) {
+                                ata_link_printk(link, KERN_ERR,
+                                                "follow-up softreset required "
+                                                "but no softreset avaliable\n");
+                                rc = -EINVAL;
+                                goto fail;
+                        }
+
+                        ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
+                        rc = ata_do_reset(link, reset, classes, deadline);
                 }
 
-                ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
-                rc = ata_do_reset(link, reset, classes, deadline);
+                /* -EAGAIN can happen if we skipped followup SRST */
+                if (rc && rc != -EAGAIN)
+                        goto fail;
+        } else {
+                if (verbose)
+                        ata_link_printk(link, KERN_INFO, "no reset method "
+                                        "available, skipping reset\n");
+                if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
+                        lflags |= ATA_LFLAG_ASSUME_ATA;
         }
 
-        /* -EAGAIN can happen if we skipped followup SRST */
-        if (rc && rc != -EAGAIN)
-                goto fail;
-
- done:
+        /*
+         * Post-reset processing
+         */
         ata_link_for_each_dev(dev, link) {
                 /* After the reset, the device state is PIO 0 and the
                  * controller state is undefined.  Reset also wakes up
@@ -2236,9 +2228,53 @@ int ata_eh_reset(struct ata_link *link, int classify,
         if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
                 link->sata_spd = (sstatus >> 4) & 0xf;
 
+        /* thaw the port */
+        if (ata_is_host_link(link))
+                ata_eh_thaw_port(ap);
+
+        /* postreset() should clear hardware SError.  Although SError
+         * is cleared during link resume, clearing SError here is
+         * necessary as some PHYs raise hotplug events after SRST.
+         * This introduces race condition where hotplug occurs between
+         * reset and here.  This race is mediated by cross checking
+         * link onlineness and classification result later.
+         */
         if (postreset)
                 postreset(link, classes);
 
+        /* clear cached SError */
+        spin_lock_irqsave(link->ap->lock, flags);
+        link->eh_info.serror = 0;
+        spin_unlock_irqrestore(link->ap->lock, flags);
+
+        /* Make sure onlineness and classification result correspond.
+         * Hotplug could have happened during reset and some
+         * controllers fail to wait while a drive is spinning up after
+         * being hotplugged causing misdetection.  By cross checking
+         * link onlineness and classification result, those conditions
+         * can be reliably detected and retried.
+         */
+        nr_known = 0;
+        ata_link_for_each_dev(dev, link) {
+                /* convert all ATA_DEV_UNKNOWN to ATA_DEV_NONE */
+                if (classes[dev->devno] == ATA_DEV_UNKNOWN)
+                        classes[dev->devno] = ATA_DEV_NONE;
+                else
+                        nr_known++;
+        }
+
+        if (classify && !nr_known && ata_link_online(link)) {
+                if (try < max_tries) {
+                        ata_link_printk(link, KERN_WARNING, "link online but "
+                                       "device misclassified, retrying\n");
+                        rc = -EAGAIN;
+                        goto fail;
+                }
+                ata_link_printk(link, KERN_WARNING,
+                               "link online but device misclassified, "
+                               "device detection might fail\n");
+        }
+
         /* reset successful, schedule revalidation */
         ata_eh_done(link, NULL, ATA_EH_RESET);
         ehc->i.action |= ATA_EH_REVALIDATE;
@@ -2587,7 +2623,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
         struct ata_link *link;
         struct ata_device *dev;
         int nr_failed_devs, nr_disabled_devs;
-        int reset, rc;
+        int rc;
         unsigned long flags;
 
         DPRINTK("ENTER\n");
@@ -2630,7 +2666,6 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
         rc = 0;
         nr_failed_devs = 0;
         nr_disabled_devs = 0;
-        reset = 0;
 
         /* if UNLOADING, finish immediately */
         if (ap->pflags & ATA_PFLAG_UNLOADING)
@@ -2644,40 +2679,24 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
                 if (ata_eh_skip_recovery(link))
                         ehc->i.action = 0;
 
-                /* do we need to reset? */
-                if (ehc->i.action & ATA_EH_RESET)
-                        reset = 1;
-
                 ata_link_for_each_dev(dev, link)
                         ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
         }
 
         /* reset */
-        if (reset) {
-                /* if PMP is attached, this function only deals with
-                 * downstream links, port should stay thawed.
-                 */
-                if (!sata_pmp_attached(ap))
-                        ata_eh_freeze_port(ap);
-
-                ata_port_for_each_link(link, ap) {
-                        struct ata_eh_context *ehc = &link->eh_context;
+        ata_port_for_each_link(link, ap) {
+                struct ata_eh_context *ehc = &link->eh_context;
 
-                        if (!(ehc->i.action & ATA_EH_RESET))
-                                continue;
+                if (!(ehc->i.action & ATA_EH_RESET))
+                        continue;
 
-                        rc = ata_eh_reset(link, ata_link_nr_vacant(link),
-                                          prereset, softreset, hardreset,
-                                          postreset);
-                        if (rc) {
-                                ata_link_printk(link, KERN_ERR,
-                                                "reset failed, giving up\n");
-                                goto out;
-                        }
+                rc = ata_eh_reset(link, ata_link_nr_vacant(link),
+                                  prereset, softreset, hardreset, postreset);
+                if (rc) {
+                        ata_link_printk(link, KERN_ERR,
+                                        "reset failed, giving up\n");
+                        goto out;
                 }
-
-                if (!sata_pmp_attached(ap))
-                        ata_eh_thaw_port(ap);
         }
 
         /* the rest */