[SCSI] libsas: improve debug statements

It's difficult to determine which domain_device is triggering error recovery,
so convert messages like:

  sas: ex 5001b4da000e703f phy08:T attached: 5001b4da000e7028
  sas: ex 5001b4da000e703f phy09:T attached: 5001b4da000e7029
  ...
  ata7: sas eh calling libata port error handler
  ata8: sas eh calling libata port error handler

...into:

  sas: ex 5001517e85cfefff phy05:T:9 attached: 5001517e85cfefe5 (stp)
  sas: ex 5001517e3b0af0bf phy11:T:8 attached: 5001517e3b0af0ab (stp)
  ...
  sas: ata7: end_device-21:1: dev error handler
  sas: ata8: end_device-20:0:5: dev error handler

which shows attached link rate, device type, and associates a
domain_device with its ata_port id to correlate messages emitted from
libata-eh.

As Doug notes, we can also take the opportunity to clarify expander phy
routing capabilities.

[dgilbert@interlog.com: clarify table2table with 'U']
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 33 insertions, 10 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 40edf520d69a..ba1ebfe991d7 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -317,6 +317,28 @@ static int local_ata_check_ready(struct ata_link *link)
         }
 }
 
+static int sas_ata_printk(const char *level, const struct domain_device *ddev,
+                          const char *fmt, ...)
+{
+        struct ata_port *ap = ddev->sata_dev.ap;
+        struct device *dev = &ddev->rphy->dev;
+        struct va_format vaf;
+        va_list args;
+        int r;
+
+        va_start(args, fmt);
+
+        vaf.fmt = fmt;
+        vaf.va = &args;
+
+        r = printk("%ssas: ata%u: %s: %pV",
+                   level, ap->print_id, dev_name(dev), &vaf);
+
+        va_end(args);
+
+        return r;
+}
+
 static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
                               unsigned long deadline)
 {
@@ -333,7 +355,7 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
         res = i->dft->lldd_I_T_nexus_reset(dev);
 
         if (res != TMF_RESP_FUNC_COMPLETE)
-                SAS_DPRINTK("%s: Unable to reset ata device?\n", __func__);
+                sas_ata_printk(KERN_DEBUG, dev, "Unable to reset ata device?\n");
 
         phy = sas_get_local_phy(dev);
         if (scsi_is_sas_phy_local(phy))
@@ -344,7 +366,7 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 
         ret = ata_wait_after_reset(link, deadline, check_ready);
         if (ret && ret != -EAGAIN)
-                ata_link_err(link, "COMRESET failed (errno=%d)\n", ret);
+                sas_ata_printk(KERN_ERR, dev, "reset failed (errno=%d)\n", ret);
 
         /* XXX: if the class changes during the reset the upper layer
          * should be informed, if the device has gone away we assume
@@ -665,7 +687,7 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie)
          * remove once all commands are completed
          */
         kref_get(&dev->kref);
-        ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
+        sas_ata_printk(KERN_DEBUG, dev, "dev error handler\n");
         ata_scsi_port_error_handler(ha->core.shost, ap);
         sas_put_device(dev);
 }
@@ -703,26 +725,27 @@ void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
                 struct list_head *done_q)
 {
         struct scsi_cmnd *cmd, *n;
-        struct ata_port *ap;
+        struct domain_device *eh_dev;
 
         do {
                 LIST_HEAD(sata_q);
-
-                ap = NULL;
+                eh_dev = NULL;
 
                 list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
                         struct domain_device *ddev = cmd_to_domain_dev(cmd);
 
                         if (!dev_is_sata(ddev) || TO_SAS_TASK(cmd))
                                 continue;
-                        if (ap && ap != ddev->sata_dev.ap)
+                        if (eh_dev && eh_dev != ddev)
                                 continue;
-                        ap = ddev->sata_dev.ap;
+                        eh_dev = ddev;
                         list_move(&cmd->eh_entry, &sata_q);
                 }
 
                 if (!list_empty(&sata_q)) {
-                        ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata cmd error handler\n");
+                        struct ata_port *ap = eh_dev->sata_dev.ap;
+
+                        sas_ata_printk(KERN_DEBUG, eh_dev, "cmd error handler\n");
                         ata_scsi_cmd_error_handler(shost, ap, &sata_q);
                         /*
                          * ata's error handler may leave the cmd on the list
@@ -738,7 +761,7 @@ void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
                         while (!list_empty(&sata_q))
                                 list_del_init(sata_q.next);
                 }
-        } while (ap);
+        } while (eh_dev);
 }
 
 void sas_ata_schedule_reset(struct domain_device *dev)