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From: Viresh Kumar <viresh.kumar@st.com>
To: <vinod.koul@intel.com>, <dan.j.williams@intel.com>
Cc: <linux@arm.linux.org.uk>, <linus.walleij@linaro.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <armando.visconti@st.com>,
	<shiraz.hashim@st.com>, <vipin.kumar@st.com>,
	<rajeev-dlh.kumar@st.com>, <deepak.sikri@st.com>,
	<vipulkumar.samar@st.com>, <amit.virdi@st.com>,
	<viresh.kumar@st.com>, <pratyush.anand@st.com>,
	<bhupesh.sharma@st.com>, <viresh.linux@gmail.com>,
	<bhavna.yadav@st.com>, <vincenzo.frascino@st.com>,
	<mirko.gardi@st.com>
Subject: [PATCH 6/8] dmaengine/dw_dmac: Don't handle block interrupts
Date: Mon, 16 Jan 2012 15:20:34 +0530	[thread overview]
Message-ID: <5de6fe5e4560f459075e2b82bbcfd04e56eedc41.1326707233.git.viresh.kumar@st.com> (raw)
In-Reply-To: <cover.1326707233.git.viresh.kumar@st.com>

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>
---
 drivers/dma/dw_dmac.c |   36 ++++++------------------------------
 1 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index f061daa..8698d3b 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);
-- 
1.7.8.110.g4cb5d


  parent reply	other threads:[~2012-01-16  9:52 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-16  9:50 [PATCH 0/9] dmaengine: Pl08x and dw_dmac updates Viresh Kumar
2012-01-16  9:50 ` [PATCH 1/8] dmaengine/dw_dmac: Hibernation support in dw_dmac Viresh Kumar
2012-01-16  9:50 ` [PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config Viresh Kumar
2012-01-17  8:37   ` Linus Walleij
2012-01-17  9:07     ` Viresh Kumar
2012-01-18 10:36       ` Linus Walleij
2012-01-18 10:40         ` Viresh Kumar
2012-01-16  9:50 ` [PATCH 3/8] dmaengine/amba-pl08x: Take flow controller info from DMA_SLAVE_CONFIG Viresh Kumar
2012-01-16  9:50 ` [PATCH 4/8] dmaengine/dw_dmac: Don't use magic number for total number of channels Viresh Kumar
2012-01-16  9:50 ` [PATCH 5/8] dmaengine/dw_dmac: Use platform_get_drvdata instead of accessing dev directly Viresh Kumar
2012-01-16 10:47   ` Sergei Shtylyov
2012-01-16 10:52     ` Viresh Kumar
2012-01-16  9:50 ` Viresh Kumar [this message]
2012-01-16  9:50 ` [PATCH 7/8] dmaengine/dw_dmac: Unmap all memory buffers after completion of slave transfers Viresh Kumar
2012-01-16 10:54   ` Russell King - ARM Linux
2012-01-16 11:44     ` Viresh Kumar
2012-01-17  8:52       ` Linus Walleij
2012-01-17  9:07         ` Viresh Kumar
2012-01-18  9:35           ` Russell King - ARM Linux
2012-01-19 17:34           ` Linus Walleij
2012-01-16  9:50 ` [PATCH 8/8] dmaengine/dw_dmac: Add support for DMA_SLAVE_CONFIG Viresh Kumar
2012-01-16 11:42   ` Viresh Kumar
2012-01-17  8:49     ` Linus Walleij
2012-01-17  9:15       ` Viresh Kumar
2012-01-17  9:19         ` Viresh Kumar
2012-01-17 10:19         ` Viresh Kumar
2012-01-17 10:10     ` Jassi Brar
2012-01-17 10:19       ` Viresh Kumar

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