dmaengine: mxs-dma: skip request_irq for NO_IRQ

In general, the mxs-dma users get separate irq for each channel,
but gpmi is special one which has only one irq shared by all gpmi
channels.  It causes mxs_dma channel allocation function fail for
all other gpmi channels except the first one calling into the
function.

The patch gets request_irq call skipped for NO_IRQ case, and leaves
this gpmi specific quirk to gpmi driver to sort out.  It will fix
above problem if gpmi driver sets chan_irq as gpmi irq for only one
channel and NO_IRQ for all the rest channels.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index 88aad4f54002..2870d919f112 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -327,10 +327,12 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
 
         memset(mxs_chan->ccw, 0, PAGE_SIZE);
 
-        ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
-                                0, "mxs-dma", mxs_dma);
-        if (ret)
-                goto err_irq;
+        if (mxs_chan->chan_irq != NO_IRQ) {
+                ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
+                                        0, "mxs-dma", mxs_dma);
+                if (ret)
+                        goto err_irq;
+        }
 
         ret = clk_enable(mxs_dma->clk);
         if (ret)