[PATCH 4.11 064/150] dmaengine: mv_xor_v2: remove interrupt coalescing

[Greg Kroah-Hartman]

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

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

From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>

commit 9dd4f319bac25334a869d9276b19eac9e478fd33 upstream.

The current implementation of interrupt coalescing doesn't work, because
it doesn't configure the coalescing timer, which is needed to make sure
we get an interrupt at some point.

As a fix for stable, we simply remove the interrupt coalescing
functionality. It will be re-introduced properly in a future commit.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/dma/mv_xor_v2.c |   25 -------------------------
 1 file changed, 25 deletions(-)

--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -246,22 +246,6 @@ static int mv_xor_v2_set_desc_size(struc
 	return MV_XOR_V2_EXT_DESC_SIZE;
 }
 
-/*
- * Set the IMSG threshold
- */
-static inline
-void mv_xor_v2_set_imsg_thrd(struct mv_xor_v2_device *xor_dev, int thrd_val)
-{
-	u32 reg;
-
-	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-
-	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-	reg |= (thrd_val << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-
-	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-}
-
 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 {
 	struct mv_xor_v2_device *xor_dev = data;
@@ -277,12 +261,6 @@ static irqreturn_t mv_xor_v2_interrupt_h
 	if (!ndescs)
 		return IRQ_NONE;
 
-	/*
-	 * Update IMSG threshold, to disable new IMSG interrupts until
-	 * end of the tasklet
-	 */
-	mv_xor_v2_set_imsg_thrd(xor_dev, MV_XOR_V2_DESC_NUM);
-
 	/* schedule a tasklet to handle descriptors callbacks */
 	tasklet_schedule(&xor_dev->irq_tasklet);
 
@@ -607,9 +585,6 @@ static void mv_xor_v2_tasklet(unsigned l
 		/* free the descriptores */
 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
 	}
-
-	/* Update IMSG threshold, to enable new IMSG interrupts */
-	mv_xor_v2_set_imsg_thrd(xor_dev, 0);
 }
 
 /*