---

yaml
---
r: 177262
b: refs/heads/master
c: d2e015d
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: adfc046740b4161cbb1f0a3ea0d4200e21113489
+refs/heads/master: d2e015d65fc692475b8513259d6afacd2cded8e8

trunk/arch/blackfin/include/asm/dma.h

@@ -10,6 +10,7 @@
 
 #include <linux/interrupt.h>
 #include <mach/dma.h>
+#include <asm/atomic.h>
 #include <asm/blackfin.h>
 #include <asm/page.h>
 
@@ -19,11 +20,6 @@
 *        Generic DMA  Declarations
 *
 ****************************************************************************/
-enum dma_chan_status {
-	DMA_CHANNEL_FREE,
-	DMA_CHANNEL_REQUESTED,
-	DMA_CHANNEL_ENABLED,
-};
 
 /*-------------------------
  * config reg bits value
@@ -104,11 +100,9 @@ struct dma_register {
 
 };
 
-struct mutex;
 struct dma_channel {
-	struct mutex dmalock;
 	const char *device_id;
-	enum dma_chan_status chan_status;
+	atomic_t chan_status;
 	volatile struct dma_register *regs;
 	struct dmasg *sg;		/* large mode descriptor */
 	unsigned int irq;
@@ -220,24 +214,19 @@ static inline void set_dma_sg(unsigned int channel, struct dmasg *sg, int ndsize
 
 static inline int dma_channel_active(unsigned int channel)
 {
-	if (dma_ch[channel].chan_status == DMA_CHANNEL_FREE)
-		return 0;
-	else
-		return 1;
+	return atomic_read(&dma_ch[channel].chan_status);
 }
 
 static inline void disable_dma(unsigned int channel)
 {
 	dma_ch[channel].regs->cfg &= ~DMAEN;
 	SSYNC();
-	dma_ch[channel].chan_status = DMA_CHANNEL_REQUESTED;
 }
 static inline void enable_dma(unsigned int channel)
 {
 	dma_ch[channel].regs->curr_x_count = 0;
 	dma_ch[channel].regs->curr_y_count = 0;
 	dma_ch[channel].regs->cfg |= DMAEN;
-	dma_ch[channel].chan_status = DMA_CHANNEL_ENABLED;
 }
 void free_dma(unsigned int channel);
 int request_dma(unsigned int channel, const char *device_id);

trunk/arch/blackfin/kernel/bfin_dma_5xx.c

@@ -37,9 +37,8 @@ static int __init blackfin_dma_init(void)
 	printk(KERN_INFO "Blackfin DMA Controller\n");
 
 	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
-		dma_ch[i].chan_status = DMA_CHANNEL_FREE;
+		atomic_set(&dma_ch[i].chan_status, 0);
 		dma_ch[i].regs = dma_io_base_addr[i];
-		mutex_init(&(dma_ch[i].dmalock));
 	}
 	/* Mark MEMDMA Channel 0 as requested since we're using it internally */
 	request_dma(CH_MEM_STREAM0_DEST, "Blackfin dma_memcpy");
@@ -60,7 +59,7 @@ static int proc_dma_show(struct seq_file *m, void *v)
 	int i;
 
 	for (i = 0; i < MAX_DMA_CHANNELS; ++i)
-		if (dma_ch[i].chan_status != DMA_CHANNEL_FREE)
+		if (dma_channel_active(i))
 			seq_printf(m, "%2d: %s\n", i, dma_ch[i].device_id);
 
 	return 0;
@@ -107,20 +106,11 @@ int request_dma(unsigned int channel, const char *device_id)
 	}
 #endif
 
-	mutex_lock(&(dma_ch[channel].dmalock));
-
-	if ((dma_ch[channel].chan_status == DMA_CHANNEL_REQUESTED)
-	    || (dma_ch[channel].chan_status == DMA_CHANNEL_ENABLED)) {
-		mutex_unlock(&(dma_ch[channel].dmalock));
+	if (atomic_cmpxchg(&dma_ch[channel].chan_status, 0, 1)) {
 		pr_debug("DMA CHANNEL IN USE  \n");
 		return -EBUSY;
-	} else {
-		dma_ch[channel].chan_status = DMA_CHANNEL_REQUESTED;
-		pr_debug("DMA CHANNEL IS ALLOCATED  \n");
 	}
 
-	mutex_unlock(&(dma_ch[channel].dmalock));
-
 #ifdef CONFIG_BF54x
 	if (channel >= CH_UART2_RX && channel <= CH_UART3_TX) {
 		unsigned int per_map;
@@ -149,7 +139,7 @@ EXPORT_SYMBOL(request_dma);
 int set_dma_callback(unsigned int channel, irq_handler_t callback, void *data)
 {
 	BUG_ON(channel >= MAX_DMA_CHANNELS ||
-			dma_ch[channel].chan_status == DMA_CHANNEL_FREE);
+			!atomic_read(&dma_ch[channel].chan_status));
 
 	if (callback != NULL) {
 		int ret;
@@ -184,7 +174,7 @@ void free_dma(unsigned int channel)
 {
 	pr_debug("freedma() : BEGIN \n");
 	BUG_ON(channel >= MAX_DMA_CHANNELS ||
-			dma_ch[channel].chan_status == DMA_CHANNEL_FREE);
+			!atomic_read(&dma_ch[channel].chan_status));
 
 	/* Halt the DMA */
 	disable_dma(channel);
@@ -194,9 +184,7 @@ void free_dma(unsigned int channel)
 		free_irq(dma_ch[channel].irq, dma_ch[channel].data);
 
 	/* Clear the DMA Variable in the Channel */
-	mutex_lock(&(dma_ch[channel].dmalock));
-	dma_ch[channel].chan_status = DMA_CHANNEL_FREE;
-	mutex_unlock(&(dma_ch[channel].dmalock));
+	atomic_set(&dma_ch[channel].chan_status, 0);
 
 	pr_debug("freedma() : END \n");
 }
@@ -210,13 +198,14 @@ int blackfin_dma_suspend(void)
 {
 	int i;
 
-	for (i = 0; i < MAX_DMA_SUSPEND_CHANNELS; ++i) {
-		if (dma_ch[i].chan_status == DMA_CHANNEL_ENABLED) {
+	for (i = 0; i < MAX_DMA_CHANNELS; ++i) {
+		if (dma_ch[i].regs->cfg & DMAEN) {
 			printk(KERN_ERR "DMA Channel %d failed to suspend\n", i);
 			return -EBUSY;
 		}
 
-		dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map;
+		if (i < MAX_DMA_SUSPEND_CHANNELS)
+			dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map;
 	}
 
 	return 0;