From b4941f35ad57df4ccce70478b782727a30d4ec20 Mon Sep 17 00:00:00 2001
From: Shaun Ruffell <sruffell@digium.com>
Date: Fri, 20 Jun 2014 12:02:49 -0500
Subject: [PATCH] wct4xxp: Move bottom half processing from tasklet to
 workqueue.

I am primarily making this change in order that the oct612x API can use a mutex as
a synchronization primitive. Mutexes can only be aquired in process context and
the wct4xxp driver calls the Oct61000InterruptServiceRoutine (which grabs a
serialization object) when tone detection is enabled.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
---
 drivers/dahdi/wct4xxp/base.c    | 31 +++++++++++++++++++++++--------
 drivers/dahdi/wct4xxp/wct4xxp.h |  7 -------
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/dahdi/wct4xxp/base.c b/drivers/dahdi/wct4xxp/base.c
index ebcdf03..98d2587 100644
--- a/drivers/dahdi/wct4xxp/base.c
+++ b/drivers/dahdi/wct4xxp/base.c
@@ -371,9 +371,14 @@ struct t4 {
 	dma_addr_t	writedma;
 	void __iomem	*membase;	/* Base address of card */
 
-	/* Flags for our bottom half */
+#define T4_CHECK_VPM		0
+#define T4_LOADING_FW		1
+#define T4_STOP_DMA		2
+#define T4_CHECK_TIMING		3
+#define T4_CHANGE_LATENCY	4
+#define T4_IGNORE_LATENCY	5
 	unsigned long checkflag;
-	struct tasklet_struct t4_tlet;
+	struct work_struct  bh_work;
 	/* Latency related additions */
 	unsigned char rxident;
 	unsigned char lastindex;
@@ -549,8 +554,6 @@ static void t4_check_sigbits(struct t4 *wc, int span);
 
 #define MAX_T4_CARDS 64
 
-static void t4_isr_bh(unsigned long data);
-
 static struct t4 *cards[MAX_T4_CARDS];
 
 struct t8_firm_header {
@@ -2116,6 +2119,8 @@ static void free_wc(struct t4 *wc)
 {
 	unsigned int x, y;
 
+	flush_scheduled_work();
+
 	for (x = 0; x < ARRAY_SIZE(wc->tspans); x++) {
 		if (!wc->tspans[x])
 			continue;
@@ -4056,9 +4061,15 @@ static void t4_increase_latency(struct t4 *wc, int newlatency)
 
 }
 
-static void t4_isr_bh(unsigned long data)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
+static void t4_work_func(void *data)
 {
-	struct t4 *wc = (struct t4 *)data;
+	struct t4 *wc = data;
+#else
+static void t4_work_func(struct work_struct *work)
+{
+	struct t4 *wc = container_of(work, struct t4, bh_work);
+#endif
 
 	if (test_bit(T4_CHANGE_LATENCY, &wc->checkflag)) {
 		if (wc->needed_latency != wc->numbufs) {
@@ -4265,7 +4276,7 @@ static irqreturn_t _t4_interrupt_gen2(int irq, void *dev_id)
 
 out:
 	if (unlikely(test_bit(T4_CHANGE_LATENCY, &wc->checkflag) || test_bit(T4_CHECK_VPM, &wc->checkflag)))
-		tasklet_schedule(&wc->t4_tlet);
+		schedule_work(&wc->bh_work);
 
 #ifndef ENABLE_WORKQUEUES
 	__t4_pci_out(wc, WC_INTR, 0);
@@ -5146,7 +5157,11 @@ static int __devinit t4_launch(struct t4 *wc)
 			      &wc->ddev->spans);
 	}
 
-	tasklet_init(&wc->t4_tlet, t4_isr_bh, (unsigned long)wc);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
+	INIT_WORK(&wc->bh_work, t4_work_func, wc);
+#else
+	INIT_WORK(&wc->bh_work, t4_work_func);
+#endif
 
 	res = dahdi_register_device(wc->ddev, &wc->dev->dev);
 	if (res) {
diff --git a/drivers/dahdi/wct4xxp/wct4xxp.h b/drivers/dahdi/wct4xxp/wct4xxp.h
index 0546160..13d5ad6 100644
--- a/drivers/dahdi/wct4xxp/wct4xxp.h
+++ b/drivers/dahdi/wct4xxp/wct4xxp.h
@@ -131,13 +131,6 @@ struct t4_reg {
 	unsigned int val;
 };
 
-#define T4_CHECK_VPM		0
-#define T4_LOADING_FW		1
-#define T4_STOP_DMA		2
-#define T4_CHECK_TIMING		3
-#define T4_CHANGE_LATENCY	4
-#define T4_IGNORE_LATENCY	5
-
 #define WCT4_GET_REGS	_IOW(DAHDI_CODE, 60, struct t4_regs)
 #define WCT4_GET_REG	_IOW(DAHDI_CODE, 61, struct t4_reg)
 #define WCT4_SET_REG	_IOW(DAHDI_CODE, 62, struct t4_reg)