[PATCH 4.19 100/421] pata_octeon_cf: avoid WARN_ON() in ata_host_activate()

[Greg Kroah-Hartman]

From: Sergey Shtylyov <s.shtylyov@xxxxxx>

[ Upstream commit bfc1f378c8953e68ccdbfe0a8c20748427488b80 ]

Iff platform_get_irq() fails (or returns IRQ0) and thus the polling mode
has to be used, ata_host_activate() hits the WARN_ON() due to 'irq_handler'
parameter being non-NULL if the polling mode is selected.  Let's only set
the pointer to the driver's IRQ handler if platform_get_irq() returns a
valid IRQ # -- this should avoid the unnecessary WARN_ON()...

Fixes: 43f01da0f279 ("MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.")
Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Link: https://lore.kernel.org/r/3a241167-f84d-1d25-5b9b-be910afbe666@xxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/ata/pata_octeon_cf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
index d3d851b014a3..ac3b1fda820f 100644
--- a/drivers/ata/pata_octeon_cf.c
+++ b/drivers/ata/pata_octeon_cf.c
@@ -898,10 +898,11 @@ static int octeon_cf_probe(struct platform_device *pdev)
 					return -EINVAL;
 				}
 
-				irq_handler = octeon_cf_interrupt;
 				i = platform_get_irq(dma_dev, 0);
-				if (i > 0)
+				if (i > 0) {
 					irq = i;
+					irq_handler = octeon_cf_interrupt;
+				}
 			}
 			of_node_put(dma_node);
 		}
-- 
2.30.2