From 4cd09feb54c97148e8792a393396f3fc31744372 Mon Sep 17 00:00:00 2001
From: Shaun Ruffell <sruffell@digium.com>
Date: Wed, 22 Jan 2014 12:24:04 -0600
Subject: [PATCH] wcte43x, wcte13xp, wcaxx: Bump irqmisses counter when there
 are DMA underruns.

This makes the behavior of IRQ misses for these drivers behave the same as the
wcte12xp, wctdm24xxp, and wct4xxp drivers.

Previously irqmisses would never increase. The presence of underruns would still
show up in dmesg as latency bumps.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
---
 drivers/dahdi/wcaxx-base.c    | 7 +++++++
 drivers/dahdi/wcte13xp-base.c | 7 +++++++
 drivers/dahdi/wcte43x-base.c  | 7 +++++++
 drivers/dahdi/wcxb.c          | 6 ++++++
 4 files changed, 27 insertions(+)

diff --git a/drivers/dahdi/wcaxx-base.c b/drivers/dahdi/wcaxx-base.c
index 504cccf..c17f1bc 100644
--- a/drivers/dahdi/wcaxx-base.c
+++ b/drivers/dahdi/wcaxx-base.c
@@ -3864,9 +3864,16 @@ static void wcaxx_back_out_gracefully(struct wcaxx *wc)
 	kfree(wc);
 }
 
+static void wcaxx_handle_error(struct wcxb *xb)
+{
+	struct wcaxx *wc = container_of(xb, struct wcaxx, xb);
+	wc->ddev->irqmisses++;
+}
+
 static const struct wcxb_operations wcxb_operations = {
 	.handle_receive = wcaxx_handle_receive,
 	.handle_transmit = wcaxx_handle_transmit,
+	.handle_error = wcaxx_handle_error,
 };
 
 struct cmd_results {
diff --git a/drivers/dahdi/wcte13xp-base.c b/drivers/dahdi/wcte13xp-base.c
index 3ab89b1..726a63c 100644
--- a/drivers/dahdi/wcte13xp-base.c
+++ b/drivers/dahdi/wcte13xp-base.c
@@ -115,10 +115,17 @@ static void te13x_handle_transmit(struct wcxb *xb, void *vfp);
 static void te13x_handle_receive(struct wcxb *xb, void *vfp);
 static void te13x_handle_interrupt(struct wcxb *xb, u32 pending);
 
+static void te13x_handle_error(struct wcxb *xb)
+{
+	struct t13x *wc = container_of(xb, struct t13x, xb);
+	wc->ddev->irqmisses++;
+}
+
 static struct wcxb_operations xb_ops = {
 	.handle_receive = te13x_handle_receive,
 	.handle_transmit = te13x_handle_transmit,
 	.handle_interrupt = te13x_handle_interrupt,
+	.handle_error = te13x_handle_error,
 };
 
 /* Maintenance Mode Registers */
diff --git a/drivers/dahdi/wcte43x-base.c b/drivers/dahdi/wcte43x-base.c
index 056e113..af7b787 100644
--- a/drivers/dahdi/wcte43x-base.c
+++ b/drivers/dahdi/wcte43x-base.c
@@ -144,10 +144,17 @@ static void t43x_handle_transmit(struct wcxb *xb, void *vfp);
 static void t43x_handle_receive(struct wcxb *xb, void *vfp);
 static void t43x_handle_interrupt(struct wcxb *xb, u32 pending);
 
+static void t43x_handle_error(struct wcxb *xb)
+{
+	struct t43x *wc = container_of(xb, struct t43x, xb);
+	wc->ddev->irqmisses++;
+}
+
 static struct wcxb_operations xb_ops = {
 	.handle_receive = t43x_handle_receive,
 	.handle_transmit = t43x_handle_transmit,
 	.handle_interrupt = t43x_handle_interrupt,
+	.handle_error = t43x_handle_error,
 };
 
 /* Maintenance Mode Registers */
diff --git a/drivers/dahdi/wcxb.c b/drivers/dahdi/wcxb.c
index 191a0b0..5ae5325 100644
--- a/drivers/dahdi/wcxb.c
+++ b/drivers/dahdi/wcxb.c
@@ -397,6 +397,12 @@ static irqreturn_t _wcxb_isr(int irq, void *dev_id)
 		if (pending & DESC_UNDERRUN) {
 			u32 reg;
 
+			/* Report the error in case drivers have any custom
+			 * methods for indicating potential data corruption. An
+			 * underrun means data loss in the TDM channel. */
+			if (xb->ops->handle_error)
+				xb->ops->handle_error(xb);
+
 			/* bump latency */
 			spin_lock(&xb->lock);