[PATCH 4.4 247/342] dmaengine: dw: fix cyclic transfer callbacks

From: Greg Kroah-Hartman
Date: Tue Mar 01 2016 - 19:28:46 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mans Rullgard <mans@xxxxxxxxx>

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@xxxxxxxxx>
Reviewed-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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);