From 09b3c323332206aaadfb7aa13efffa82e7719b35 Mon Sep 17 00:00:00 2001 From: Russell King - ARM Linux Date: Mon, 3 Jan 2011 22:39:53 +0000 Subject: [PATCH] ARM: PL08x: assign ccfg DMA request signal in prep_phy_channel() There is no need to wait until we start processing a tx descriptor before setting up the DMA request selection in the ccfg register. We know which channel and request will be used in prep_phy_channel(), so setup the ccfg request selection at txd creation time in prep_phy_channel(). Signed-off-by: Russell King Acked-by: Linus Walleij Signed-off-by: Dan Williams --- drivers/dma/amba-pl08x.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index 75f9e2d..f0a2988 100644 --- a/drivers/dma/amba-pl08x.c +++ b/drivers/dma/amba-pl08x.c @@ -194,18 +194,10 @@ static void pl08x_start_txd(struct pl08x_dma_chan *plchan, struct pl08x_driver_data *pl08x = plchan->host; struct pl08x_phy_chan *phychan = plchan->phychan; struct pl08x_lli *lli = &txd->llis_va[0]; - u32 val, ccfg = txd->ccfg; + u32 val; plchan->at = txd; - /* Assign the flow control signal to this channel */ - if (txd->direction == DMA_TO_DEVICE) - /* Select signal as destination */ - ccfg |= phychan->signal << PL080_CONFIG_DST_SEL_SHIFT; - else if (txd->direction == DMA_FROM_DEVICE) - /* Select signal as source */ - ccfg |= phychan->signal << PL080_CONFIG_SRC_SEL_SHIFT; - /* Wait for channel inactive */ while (pl08x_phy_channel_busy(phychan)) cpu_relax(); @@ -214,13 +206,13 @@ static void pl08x_start_txd(struct pl08x_dma_chan *plchan, "WRITE channel %d: csrc=0x%08x, cdst=0x%08x, " "clli=0x%08x, cctl=0x%08x, ccfg=0x%08x\n", phychan->id, lli->src, lli->dst, lli->lli, lli->cctl, - ccfg); + txd->ccfg); writel(lli->src, phychan->base + PL080_CH_SRC_ADDR); writel(lli->dst, phychan->base + PL080_CH_DST_ADDR); writel(lli->lli, phychan->base + PL080_CH_LLI); writel(lli->cctl, phychan->base + PL080_CH_CONTROL); - writel(ccfg, phychan->base + PL080_CH_CONFIG); + writel(txd->ccfg, phychan->base + PL080_CH_CONFIG); /* Enable the DMA channel */ /* Do not access config register until channel shows as disabled */ @@ -1001,6 +993,12 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan, return -EBUSY; } ch->signal = ret; + + /* Assign the flow control signal to this channel */ + if (txd->direction == DMA_TO_DEVICE) + txd->ccfg |= ch->signal << PL080_CONFIG_DST_SEL_SHIFT; + else if (txd->direction == DMA_FROM_DEVICE) + txd->ccfg |= ch->signal << PL080_CONFIG_SRC_SEL_SHIFT; } dev_dbg(&pl08x->adev->dev, "allocated physical channel %d and signal %d for xfer on %s\n", -- 2.7.4