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Commit ff7b05f2 authored by Viresh Kumar's avatar Viresh Kumar Committed by Vinod Koul
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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: default avatarViresh Kumar <viresh.kumar@st.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
parent 6c618c9d

drivers/dma/dw_dmac.c

+6 −30
Original line number Diff line number Diff line
@@ -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);