sata_nv: give up hardreset on nf2

[safe/jmp/linux-2.6] / drivers / ata / libata-eh.c

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 90092c1..ce2ef04 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -82,6 +82,10 @@ enum {
        ATA_EH_FASTDRAIN_INTERVAL       =  3000,
 
        ATA_EH_UA_TRIES                 = 5,
+
+       /* probe speed down parameters, see ata_eh_schedule_probe() */
+       ATA_EH_PROBE_TRIAL_INTERVAL     = 60000,        /* 1 min */
+       ATA_EH_PROBE_TRIALS             = 2,
 };
 
 /* The following table determines how we sequence resets.  Each entry
@@ -1875,7 +1879,7 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev,
        /* speed down? */
        if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
                /* speed down SATA link speed if possible */
-               if (sata_down_spd_limit(link) == 0) {
+               if (sata_down_spd_limit(link, 0) == 0) {
                        action |= ATA_EH_RESET;
                        goto done;
                }
@@ -2627,11 +2631,11 @@ int ata_eh_reset(struct ata_link *link, int classify,
        }
 
        if (try == max_tries - 1) {
-               sata_down_spd_limit(link);
+               sata_down_spd_limit(link, 0);
                if (slave)
-                       sata_down_spd_limit(slave);
+                       sata_down_spd_limit(slave, 0);
        } else if (rc == -EPIPE)
-               sata_down_spd_limit(failed_link);
+               sata_down_spd_limit(failed_link, 0);
 
        if (hardreset)
                reset = hardreset;
@@ -2975,9 +2979,24 @@ static int ata_eh_skip_recovery(struct ata_link *link)
        return 1;
 }
 
+static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg)
+{
+       u64 interval = msecs_to_jiffies(ATA_EH_PROBE_TRIAL_INTERVAL);
+       u64 now = get_jiffies_64();
+       int *trials = void_arg;
+
+       if (ent->timestamp < now - min(now, interval))
+               return -1;
+
+       (*trials)++;
+       return 0;
+}
+
 static int ata_eh_schedule_probe(struct ata_device *dev)
 {
        struct ata_eh_context *ehc = &dev->link->eh_context;
+       struct ata_link *link = ata_dev_phys_link(dev);
+       int trials = 0;
 
        if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
            (ehc->did_probe_mask & (1 << dev->devno)))
@@ -2990,6 +3009,25 @@ static int ata_eh_schedule_probe(struct ata_device *dev)
        ehc->saved_xfer_mode[dev->devno] = 0;
        ehc->saved_ncq_enabled &= ~(1 << dev->devno);
 
+       /* Record and count probe trials on the ering.  The specific
+        * error mask used is irrelevant.  Because a successful device
+        * detection clears the ering, this count accumulates only if
+        * there are consecutive failed probes.
+        *
+        * If the count is equal to or higher than ATA_EH_PROBE_TRIALS
+        * in the last ATA_EH_PROBE_TRIAL_INTERVAL, link speed is
+        * forced to 1.5Gbps.
+        *
+        * This is to work around cases where failed link speed
+        * negotiation results in device misdetection leading to
+        * infinite DEVXCHG or PHRDY CHG events.
+        */
+       ata_ering_record(&dev->ering, 0, AC_ERR_OTHER);
+       ata_ering_map(&dev->ering, ata_count_probe_trials_cb, &trials);
+
+       if (trials > ATA_EH_PROBE_TRIALS)
+               sata_down_spd_limit(link, 1);
+
        return 1;
 }
 
@@ -2997,7 +3035,11 @@ static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
 {
        struct ata_eh_context *ehc = &dev->link->eh_context;
 
-       ehc->tries[dev->devno]--;
+       /* -EAGAIN from EH routine indicates retry without prejudice.
+        * The requester is responsible for ensuring forward progress.
+        */
+       if (err != -EAGAIN)
+               ehc->tries[dev->devno]--;
 
        switch (err) {
        case -ENODEV:
@@ -3011,7 +3053,7 @@ static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
                        /* This is the last chance, better to slow
                         * down than lose it.
                         */
-                       sata_down_spd_limit(ata_dev_phys_link(dev));
+                       sata_down_spd_limit(ata_dev_phys_link(dev), 0);
                        if (dev->pio_mode > XFER_PIO_0)
                                ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
                }