firewire: ohci: be noisy about temporary and final regAccessFail eventso2micro

If the retry loop needs to be engaged but succeeds in the end, print
how many tries it took.

Also, if regAccessFail happened transiently or terminally, dump the stack
to see in which context the event happened.

Plus a trivial adjustment of a parameter variable.

1 files changed, 29 insertions, 8 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 79bddf556d063e..7f59511595566e 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -326,7 +326,7 @@ static const struct {
 static int param_quirks;
 module_param_named(quirks, param_quirks, int, 0644);
 
-static int param_cycle_timer_hard_fail = 1;
+static bool param_cycle_timer_hard_fail = true;
 module_param_named(cycle_timer_hard_fail, param_cycle_timer_hard_fail, bool, 0644);
 
 static int param_sclk_retries = 20;
@@ -587,8 +587,14 @@ static int reg_rw_sclk(struct fw_ohci *ohci, int offset, u32 *data,
 		ret = check_reg_access_fail(ohci);
 		spin_unlock_irqrestore(&ohci->sclk_domain_reg_lock, flags);
 
-		if (ret != -EAGAIN)
-			return ret;
+		if (ret != -EAGAIN) {
+			if (i)
+				dev_notice(ohci->card.device,
+					   "reg_rw_sclk took %d %s retries to %s register 0x%03x\n",
+					   i, can_sleep ? "sleeping" : "busy",
+					   read ? "read" : "write", offset);
+			goto out;
+		}
 		if (i == param_sclk_retries)
 			break;
 		if (can_sleep)
@@ -596,6 +602,8 @@ static int reg_rw_sclk(struct fw_ohci *ohci, int offset, u32 *data,
 	}
 	dev_err(ohci->card.device, "SClk is off, cannot %s register 0x%03x\n",
 		read ? "read" : "write", offset);
+ out:
+	dump_stack();
 
 	return ret;
 }
@@ -1641,7 +1649,7 @@ static void handle_local_lock(struct fw_ohci *ohci,
 			      struct fw_packet *packet, u32 csr)
 {
 	struct fw_packet response;
-	int tcode, length, ext_tcode, sel, try;
+	int tcode, length, ext_tcode, sel, try, err;
 	__be32 *payload, lock_old;
 	u32 lock_arg, lock_data, reg;
 	unsigned long flags;
@@ -1673,12 +1681,14 @@ static void handle_local_lock(struct fw_ohci *ohci,
 
 	for (try = 0; try < 20; try++) {
 		reg = reg_read(ohci, OHCI1394_CSRControl);
-		if (check_reg_access_fail(ohci))
+		err = check_reg_access_fail(ohci);
+		if (err)
 			break;
 
 		if (reg & OHCI1394_CSRControl_csrDone) {
 			lock_old = cpu_to_be32(reg_read(ohci, OHCI1394_CSRData));
-			if (check_reg_access_fail(ohci))
+			err = check_reg_access_fail(ohci);
+			if (err)
 				break;
 
 			fw_fill_response(&response, packet->header,
@@ -1687,8 +1697,13 @@ static void handle_local_lock(struct fw_ohci *ohci,
 			goto out_unlock;
 		}
 	}
-
-	dev_err(ohci->card.device, "swap not done (CSR lock timeout)\n");
+	if (err == -EAGAIN) {
+		dev_err(ohci->card.device,
+			"SClk is off, cannot read CSRControl or CSRData\n");
+		dump_stack();
+	} else {
+		dev_err(ohci->card.device, "swap not done (CSR lock timeout)\n");
+	}
 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
 
  out_unlock:
@@ -1875,6 +1890,7 @@ static int get_cycle_time(struct fw_ohci *ohci, u32 *value)
 			return ret;
 	}
 	dev_err(ohci->card.device, "SClk is off, cannot read cycle timer\n");
+	dump_stack();
 
 	return ret;
 }
@@ -3081,6 +3097,11 @@ static int set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
 	ret = check_reg_access_fail(ohci);
 	if (ret == 0)
 		ohci->mc_channels = channels;
+	if (ret == -EAGAIN) {
+		dev_err(ohci->card.device,
+			"SClk is off, cannot write IRMultiChanMask\n");
+		dump_stack();
+	}
 	spin_unlock_irqrestore(&ohci->sclk_domain_reg_lock, flags);
 
 	return ret;