---

yaml
---
r: 142556
b: refs/heads/master
c: 11d6f59
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4160bde2d83d1c66e9c774c48015a13733fe9aba
+refs/heads/master: 11d6f5995137ba4dc49e9337185ac0a8753f8f69

trunk/drivers/spi/spi_bfin5xx.c

@@ -761,11 +761,10 @@ static void pump_transfers(unsigned long data)
 	if (!full_duplex && drv_data->cur_chip->enable_dma
 				&& drv_data->len > 6) {
 
-		unsigned long dma_start_addr;
+		unsigned long dma_start_addr, flags;
 
 		disable_dma(drv_data->dma_channel);
 		clear_dma_irqstat(drv_data->dma_channel);
-		bfin_spi_disable(drv_data);
 
 		/* config dma channel */
 		dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
@@ -796,8 +795,7 @@ static void pump_transfers(unsigned long data)
 			enable_dma(drv_data->dma_channel);
 
 			/* start SPI transfer */
-			write_CTRL(drv_data,
-				(cr | BIT_CTL_TIMOD_DMA_TX | BIT_CTL_ENABLE));
+			write_CTRL(drv_data, cr | BIT_CTL_TIMOD_DMA_TX);
 
 			/* just return here, there can only be one transfer
 			 * in this mode
@@ -842,14 +840,22 @@ static void pump_transfers(unsigned long data)
 		} else
 			BUG();
 
-		/* start dma */
-		dma_enable_irq(drv_data->dma_channel);
-		set_dma_config(drv_data->dma_channel, dma_config);
+		/* oh man, here there be monsters ... and i dont mean the
+		 * fluffy cute ones from pixar, i mean the kind that'll eat
+		 * your data, kick your dog, and love it all.  do *not* try
+		 * and change these lines unless you (1) heavily test DMA
+		 * with SPI flashes on a loaded system (e.g. ping floods),
+		 * (2) know just how broken the DMA engine interaction with
+		 * the SPI peripheral is, and (3) have someone else to blame
+		 * when you screw it all up anyways.
+		 */
 		set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
+		set_dma_config(drv_data->dma_channel, dma_config);
+		local_irq_save(flags);
 		enable_dma(drv_data->dma_channel);
-
-		/* start SPI transfer */
-		write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
+		write_CTRL(drv_data, cr);
+		dma_enable_irq(drv_data->dma_channel);
+		local_irq_restore(flags);
 
 	} else {
 		/* IO mode write then read */