From 4a46ba36e25dcff1d30eb1681135c3c10af71c16 Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Mon, 2 Jul 2012 13:52:07 +0530 Subject: dma: tegra: fix residual calculation for cyclic case In cyclic mode of DMA, the byte transferred can be more than the requested size and in this case, calculating residuals based on the current position of DMA transfer to bytes requested i.e. bytes required to transfer to reach bytes requested from current DMA position. Signed-off-by: Laxman Dewangan Acked-by: Stephen Warren Signed-off-by: Vinod Koul --- drivers/dma/tegra20-apb-dma.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index c0836a7..8e0ea24 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -731,6 +731,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc, struct tegra_dma_sg_req *sg_req; enum dma_status ret; unsigned long flags; + unsigned int residual; spin_lock_irqsave(&tdc->lock, flags); @@ -744,9 +745,10 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc, /* Check on wait_ack desc status */ list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) { if (dma_desc->txd.cookie == cookie) { - dma_set_residue(txstate, - dma_desc->bytes_requested - - dma_desc->bytes_transferred); + residual = dma_desc->bytes_requested - + (dma_desc->bytes_transferred % + dma_desc->bytes_requested); + dma_set_residue(txstate, residual); ret = dma_desc->dma_status; spin_unlock_irqrestore(&tdc->lock, flags); return ret; @@ -757,9 +759,10 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc, list_for_each_entry(sg_req, &tdc->pending_sg_req, node) { dma_desc = sg_req->dma_desc; if (dma_desc->txd.cookie == cookie) { - dma_set_residue(txstate, - dma_desc->bytes_requested - - dma_desc->bytes_transferred); + residual = dma_desc->bytes_requested - + (dma_desc->bytes_transferred % + dma_desc->bytes_requested); + dma_set_residue(txstate, residual); ret = dma_desc->dma_status; spin_unlock_irqrestore(&tdc->lock, flags); return ret; -- cgit v1.1