Re: [PATCH 2/2] OMAP: DMA: clear interrupt status correctly

[Adrian Hunter <adrian.hunter@nokia.com>]

 From fffa19df17d73c1ed2e8c65c0b6604ee1dddff84 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@nokia.com>
Date: Wed, 24 Nov 2010 13:23:21 +0200
Subject: [PATCH] OMAP: DMA: clear interrupt status correctly

When clearing the DMA channel, clear all status bits.

When handling a DMA interrupt, clear only the interrupt
status bits that have been read and are passed to the
channel's interrupt handler, not every status bit.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
  arch/arm/plat-omap/dma.c |    7 +++----
  1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index c4b2b47..8536308 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -53,7 +53,7 @@ enum { DMA_CHAIN_STARTED, DMA_CHAIN_NOTSTARTED };
  #endif
  
  #define OMAP_DMA_ACTIVE			0x01
-#define OMAP2_DMA_CSR_CLEAR_MASK	0xffe
+#define OMAP2_DMA_CSR_CLEAR_MASK	0xffffffff
  
  #define OMAP_FUNC_MUX_ARM_BASE		(0xfffe1000 + 0xec)
  
@@ -1873,7 +1873,7 @@ static int omap2_dma_handle_ch(int ch)
  		printk(KERN_INFO "DMA misaligned error with device %d\n",
  		       dma_chan[ch].dev_id);
  
-	p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, ch);
+	p->dma_write(status, CSR, ch);
  	p->dma_write(1 << ch, IRQSTATUS_L0, ch);
  	/* read back the register to flush the write */
  	p->dma_read(IRQSTATUS_L0, ch);
@@ -1893,10 +1893,9 @@ static int omap2_dma_handle_ch(int ch)
  			OMAP_DMA_CHAIN_INCQHEAD(chain_id);
  
  		status = p->dma_read(CSR, ch);
+		p->dma_write(status, CSR, ch);
  	}
  
-	p->dma_write(status, CSR, ch);
-
  	if (likely(dma_chan[ch].callback != NULL))
  		dma_chan[ch].callback(ch, status, dma_chan[ch].data);
  
-- 
1.7.0.4