Patch "dmaengine: mv_xor_v2: remove interrupt coalescing" has been added to the 4.11-stable tree

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

dmaengine: mv_xor_v2: remove interrupt coalescing

to the 4.11-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-mv_xor_v2-remove-interrupt-coalescing.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Thomas Petazzoni <[email protected]>
Date: Fri, 5 May 2017 11:57:49 +0200
Subject: dmaengine: mv_xor_v2: remove interrupt coalescing

From: Thomas Petazzoni <[email protected]>

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.

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

@@ -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);
 }
 
 /*

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/dmaengine-mv_xor_v2-properly-handle-wrapping-in-the-array-of-hw-descriptors.patch queue-4.11/dmaengine-mv_xor_v2-enable-xor-engine-after-its-configuration.patch queue-4.11/dmaengine-mv_xor_v2-set-dma-mask-to-40-bits.patch queue-4.11/dmaengine-mv_xor_v2-do-not-use-descriptors-not-acked-by-async_tx.patch queue-4.11/dmaengine-mv_xor_v2-handle-mv_xor_v2_prep_sw_desc-error-properly.patch queue-4.11/dmaengine-mv_xor_v2-remove-interrupt-coalescing.patch queue-4.11/dmaengine-mv_xor_v2-fix-tx_submit-implementation.patch