2 files changed, 13 insertions, 35 deletions

diff --git a/arch/blackfin/include/asm/dma.h b/arch/blackfin/include/asm/dma.h
index c9a59622e23f..e3c0dfa73d1b 100644
--- a/arch/blackfin/include/asm/dma.h
+++ b/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);
diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 3946aff4f414..639dcee5611c 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/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;