A couple of hardware registers need to be set to reflect which
interrupts have been allocated to the device. Each register is 32-bit
wide and can receive four 8-bit values. If we provide any other interrupt
number than four, the irq_num variable will never be 0 within the while
check and the while block will loop forever.

There is an easy way to prevent this: just break the for loop
when we reach "irq_num == 0", which anyway means all interrupts have
been processed.

Cc: stable@vger.kernel.org
Fixes: 17ce252266c7 ("dmaengine: xilinx: xdma: Add xilinx xdma driver")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
  drivers/dma/xilinx/xdma.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index 93ee298d52b8..359123526dd0 100644
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c

@@ -668,6 +668,8 @@ static int xdma_set_vector_reg(struct xdma_device *xdev, u32 vec_tbl_start,
  			val |= irq_start << shift;
  			irq_start++;
  			irq_num--;
+			if (!irq_num)
+				break;