ata: libata: add reset tracepoints

To follow the flow of control we should be using tracepoints, as
they will tie in with the actual I/O flow and deliver a better
overview about what it happening.
This patch adds tracepoints for hard reset, soft reset, and postreset
and adds them in the libata-eh control flow.
With that we can drop the reset DPRINTK calls in the various drivers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 1d4a6f1..043a1c8 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2596,12 +2596,19 @@ int ata_eh_reset(struct ata_link *link, int classify,
 
 		/* mark that this EH session started with reset */
 		ehc->last_reset = jiffies;
-		if (reset == hardreset)
+		if (reset == hardreset) {
 			ehc->i.flags |= ATA_EHI_DID_HARDRESET;
-		else
+			trace_ata_link_hardreset_begin(link, classes, deadline);
+		} else {
 			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
+			trace_ata_link_softreset_begin(link, classes, deadline);
+		}
 
 		rc = ata_do_reset(link, reset, classes, deadline, true);
+		if (reset == hardreset)
+			trace_ata_link_hardreset_end(link, classes, rc);
+		else
+			trace_ata_link_softreset_end(link, classes, rc);
 		if (rc && rc != -EAGAIN) {
 			failed_link = link;
 			goto fail;
@@ -2615,8 +2622,11 @@ int ata_eh_reset(struct ata_link *link, int classify,
 				ata_link_info(slave, "hard resetting link\n");
 
 			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
+			trace_ata_slave_hardreset_begin(slave, classes,
+							deadline);
 			tmp = ata_do_reset(slave, reset, classes, deadline,
 					   false);
+			trace_ata_slave_hardreset_end(slave, classes, tmp);
 			switch (tmp) {
 			case -EAGAIN:
 				rc = -EAGAIN;
@@ -2644,7 +2654,9 @@ int ata_eh_reset(struct ata_link *link, int classify,
 			}
 
 			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
+			trace_ata_link_softreset_begin(link, classes, deadline);
 			rc = ata_do_reset(link, reset, classes, deadline, true);
+			trace_ata_link_softreset_end(link, classes, rc);
 			if (rc) {
 				failed_link = link;
 				goto fail;
@@ -2698,8 +2710,11 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	 */
 	if (postreset) {
 		postreset(link, classes);
-		if (slave)
+		trace_ata_link_postreset(link, classes, rc);
+		if (slave) {
 			postreset(slave, classes);
+			trace_ata_slave_postreset(slave, classes, rc);
+		}
 	}
 
 	/*