Patch "dmaengine: dw: fix cyclic transfer callbacks" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    dmaengine: dw: fix cyclic transfer callbacks

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dmaengine-dw-fix-cyclic-transfer-callbacks.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 2895b2cad6e7a95104cf396e5330054453382ae1 Mon Sep 17 00:00:00 2001
From: Mans Rullgard <mans@mansr.com>
Date: Mon, 11 Jan 2016 13:04:29 +0000
Subject: dmaengine: dw: fix cyclic transfer callbacks

From: Mans Rullgard <mans@mansr.com>

commit 2895b2cad6e7a95104cf396e5330054453382ae1 upstream.

Cyclic transfer callbacks rely on block completion interrupts which were
disabled in commit ff7b05f29fd4 ("dmaengine/dw_dmac: Don't handle block
interrupts").  This re-enables block interrupts so the cyclic callbacks
can work.  Other transfer types are not affected as they set the INT_EN
bit only on the last block.

Fixes: ff7b05f29fd4 ("dmaengine/dw_dmac: Don't handle block interrupts")
Signed-off-by: Mans Rullgard <mans@mansr.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/dma/dw/core.c |   21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -156,6 +156,7 @@ static void dwc_initialize(struct dw_dma
 
 	/* 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;
@@ -536,16 +537,17 @@ 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_err, u32 status_xfer)
+		u32 status_block, u32 status_err, u32 status_xfer)
 {
 	unsigned long flags;
 
-	if (dwc->mask) {
+	if (status_block & 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;
@@ -577,6 +579,7 @@ static void dwc_handle_cyclic(struct dw_
 		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);
 
@@ -593,10 +596,12 @@ static void dw_dma_tasklet(unsigned long
 {
 	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);
 
@@ -605,7 +610,8 @@ static void dw_dma_tasklet(unsigned long
 	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_err, status_xfer);
+			dwc_handle_cyclic(dw, dwc, status_block, status_err,
+					status_xfer);
 		else if (status_err & (1 << i))
 			dwc_handle_error(dw, dwc);
 		else if (status_xfer & (1 << i))
@@ -616,6 +622,7 @@ static void dw_dma_tasklet(unsigned long
 	 * 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);
 }
 
@@ -635,6 +642,7 @@ static irqreturn_t dw_dma_interrupt(int
 	 * 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);
@@ -645,6 +653,7 @@ static irqreturn_t dw_dma_interrupt(int
 
 		/* 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);
@@ -1111,6 +1120,7 @@ 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);
@@ -1216,6 +1226,7 @@ static void dwc_free_chan_resources(stru
 
 	/* 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);
@@ -1458,6 +1469,7 @@ void dw_dma_cyclic_free(struct dma_chan
 
 	dwc_chan_disable(dw, dwc);
 
+	dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 	dma_writel(dw, CLEAR.ERROR, dwc->mask);
 	dma_writel(dw, CLEAR.XFER, dwc->mask);
 
@@ -1546,9 +1558,6 @@ int dw_dma_probe(struct dw_dma_chip *chi
 	/* Force dma off, just in case */
 	dw_dma_off(dw);
 
-	/* Disable BLOCK interrupts as well */
-	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
-
 	/* Create a pool of consistent memory blocks for hardware descriptors */
 	dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
 					 sizeof(struct dw_desc), 4, 0);


Patches currently in stable-queue which might be from mans@mansr.com are

queue-4.4/dmaengine-dw-fix-cyclic-transfer-callbacks.patch
queue-4.4/dmaengine-dw-fix-cyclic-transfer-setup.patch
queue-4.4/dmaengine-dw-disable-block-irqs-for-non-cyclic-xfer.patch