ARM: S3C64XX: DMA: Callback with correct buffer pointer
authorJassi Brar <jassi.brar@samsung.com>
Thu, 5 Nov 2009 04:44:33 +0000 (13:44 +0900)
committerBen Dooks <ben-linux@fluff.org>
Mon, 9 Nov 2009 23:51:03 +0000 (23:51 +0000)
buffdone callback should be called per buffer request with pointer
to the latest serviced request.
'next' should point to the one next to currently active.

Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
arch/arm/plat-s3c64xx/dma.c

index a94281bb84d6879e9088044a537472c813364974..7d12eb8fa58dc36a41176d80ffd2c93b1ecd5b0e 100644 (file)
@@ -576,6 +576,7 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
        errstat = readl(dmac->regs + PL080_ERR_STATUS);
 
        for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
+               struct s3c64xx_dma_buff *buff;
 
                if (!(errstat & bit) && !(tcstat & bit))
                        continue;
@@ -591,7 +592,33 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
                if (errstat & bit)
                        writel(bit, dmac->regs + PL080_ERR_CLEAR);
 
-               s3c64xx_dma_bufffdone(chan, chan->curr, res);
+               /* 'next' points to the buffer that is next to the
+                * currently active buffer.
+                * For CIRCULAR queues, 'next' will be same as 'curr'
+                * when 'end' is the active buffer.
+                */
+               buff = chan->curr;
+               while (buff && buff != chan->next
+                               && buff->next != chan->next)
+                       buff = buff->next;
+
+               if (!buff)
+                       BUG();
+
+               if (buff == chan->next)
+                       buff = chan->end;
+
+               s3c64xx_dma_bufffdone(chan, buff, res);
+
+               /* Update 'next' */
+               buff = chan->next;
+               if (chan->next == chan->end) {
+                       chan->next = chan->curr;
+                       if (!(chan->flags & S3C2410_DMAF_CIRCULAR))
+                               chan->end = NULL;
+               } else {
+                       chan->next = buff->next;
+               }
        }
 
        return IRQ_HANDLED;