[3.11.y.z extended stable] Patch "dma: dw: allow shared interrupts" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    dma: dw: allow shared interrupts

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bf1e74fcb578a4dc1610f1dc51d5072c5b5f898f Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Date: Mon, 15 Jul 2013 15:04:39 +0300
Subject: dma: dw: allow shared interrupts

commit 3783cef876e0f24e93a11f1a76cc0b3fe7ea8d94 upstream.

In the PC world is quite possible that devices are sharing the same interrupt
line. The patch prepares dw_dmac driver to such cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar at linaro.org>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/dma/dw/core.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index eea479c12173..1292a6eda60f 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -644,10 +644,13 @@ static void dw_dma_tasklet(unsigned long data)
 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 {
 	struct dw_dma *dw = dev_id;
-	u32 status;
+	u32 status = dma_readl(dw, STATUS_INT);

-	dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__,
-			dma_readl(dw, STATUS_INT));
+	dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
+
+	/* Check if we have any interrupt from the DMAC */
+	if (!status)
+		return IRQ_NONE;

 	/*
 	 * Just disable the interrupts. We'll turn them back on in the
@@ -1560,8 +1563,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 	/* Disable BLOCK interrupts as well */
 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);

-	err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt, 0,
-			       "dw_dmac", dw);
+	err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt,
+			       IRQF_SHARED, "dw_dmac", dw);
 	if (err)
 		return err;

--
1.9.1