From ff7b05f29fd4db810021d905e2dad95ab4fe2984 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Wed, 1 Feb 2012 16:12:23 +0530 Subject: dmaengine/dw_dmac: Don't handle block interrupts Block interrupts give interrupt on completion of every LLI, which is actually too much interrupts. This is just not required for current functioning of dw_dmac. So, just don't handle them at all. Signed-off-by: Viresh Kumar Signed-off-by: Vinod Koul --- drivers/dma/dw_dmac.c | 36 ++++++------------------------------ 1 file changed, 6 insertions(+), 30 deletions(-) (limited to 'drivers') diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index f3aecb3c0343..5d7b199208d9 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -192,7 +192,6 @@ static void dwc_initialize(struct dw_dma_chan *dwc) /* Enable interrupts */ channel_set_bit(dw, MASK.XFER, dwc->mask); - channel_set_bit(dw, MASK.BLOCK, dwc->mask); channel_set_bit(dw, MASK.ERROR, dwc->mask); dwc->initialized = true; @@ -329,12 +328,6 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) unsigned long flags; spin_lock_irqsave(&dwc->lock, flags); - /* - * Clear block interrupt flag before scanning so that we don't - * miss any, and read LLP before RAW_XFER to ensure it is - * valid if we decide to scan the list. - */ - dma_writel(dw, CLEAR.BLOCK, dwc->mask); llp = channel_readl(dwc, LLP); status_xfer = dma_readl(dw, RAW.XFER); @@ -470,17 +463,16 @@ EXPORT_SYMBOL(dw_dma_get_dst_addr); /* called with dwc->lock held and all DMAC interrupts disabled */ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc, - u32 status_block, u32 status_err, u32 status_xfer) + u32 status_err, u32 status_xfer) { unsigned long flags; - if (status_block & dwc->mask) { + if (dwc->mask) { void (*callback)(void *param); void *callback_param; dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n", channel_readl(dwc, LLP)); - dma_writel(dw, CLEAR.BLOCK, dwc->mask); callback = dwc->cdesc->period_callback; callback_param = dwc->cdesc->period_callback_param; @@ -520,7 +512,6 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc, channel_writel(dwc, CTL_LO, 0); channel_writel(dwc, CTL_HI, 0); - dma_writel(dw, CLEAR.BLOCK, dwc->mask); dma_writel(dw, CLEAR.ERROR, dwc->mask); dma_writel(dw, CLEAR.XFER, dwc->mask); @@ -537,36 +528,29 @@ static void dw_dma_tasklet(unsigned long data) { struct dw_dma *dw = (struct dw_dma *)data; struct dw_dma_chan *dwc; - u32 status_block; u32 status_xfer; u32 status_err; int i; - status_block = dma_readl(dw, RAW.BLOCK); status_xfer = dma_readl(dw, RAW.XFER); status_err = dma_readl(dw, RAW.ERROR); - dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n", - status_block, status_err); + dev_vdbg(dw->dma.dev, "tasklet: status_err=%x\n", status_err); for (i = 0; i < dw->dma.chancnt; i++) { dwc = &dw->chan[i]; if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) - dwc_handle_cyclic(dw, dwc, status_block, status_err, - status_xfer); + dwc_handle_cyclic(dw, dwc, status_err, status_xfer); else if (status_err & (1 << i)) dwc_handle_error(dw, dwc); - else if ((status_block | status_xfer) & (1 << i)) + else if (status_xfer & (1 << i)) dwc_scan_descriptors(dw, dwc); } /* - * Re-enable interrupts. Block Complete interrupts are only - * enabled if the INT_EN bit in the descriptor is set. This - * will trigger a scan before the whole list is done. + * Re-enable interrupts. */ channel_set_bit(dw, MASK.XFER, dw->all_chan_mask); - channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask); channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask); } @@ -583,7 +567,6 @@ static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) * softirq handler. */ channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); - channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); status = dma_readl(dw, STATUS_INT); @@ -594,7 +577,6 @@ static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) /* Try to recover */ channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1); - channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1); channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1); channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1); channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1); @@ -1068,7 +1050,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan) /* Disable interrupts */ channel_clear_bit(dw, MASK.XFER, dwc->mask); - channel_clear_bit(dw, MASK.BLOCK, dwc->mask); channel_clear_bit(dw, MASK.ERROR, dwc->mask); spin_unlock_irqrestore(&dwc->lock, flags); @@ -1120,7 +1101,6 @@ int dw_dma_cyclic_start(struct dma_chan *chan) return -EBUSY; } - dma_writel(dw, CLEAR.BLOCK, dwc->mask); dma_writel(dw, CLEAR.ERROR, dwc->mask); dma_writel(dw, CLEAR.XFER, dwc->mask); @@ -1322,7 +1302,6 @@ void dw_dma_cyclic_free(struct dma_chan *chan) while (dma_readl(dw, CH_EN) & dwc->mask) cpu_relax(); - dma_writel(dw, CLEAR.BLOCK, dwc->mask); dma_writel(dw, CLEAR.ERROR, dwc->mask); dma_writel(dw, CLEAR.XFER, dwc->mask); @@ -1347,7 +1326,6 @@ static void dw_dma_off(struct dw_dma *dw) dma_writel(dw, CFG, 0); channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); - channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); @@ -1449,13 +1427,11 @@ static int __init dw_probe(struct platform_device *pdev) /* Clear/disable all interrupts on all channels. */ dma_writel(dw, CLEAR.XFER, dw->all_chan_mask); - dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask); dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask); dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask); dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask); channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); - channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); -- cgit v1.2.3-55-g7522