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 <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index f3aecb3..5d7b199 100644 (file)
--- 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);