From 9b08284bf22f438baa2d6b68015ff17ddb431a61 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:33 +0900 Subject: [PATCH] ARM: S3C64XX: DMA: Callback with correct buffer pointer 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 Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index a94281bb84d6..7d12eb8fa58d 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -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; -- GitLab