pata_arasan_cf: fix IRQ check

[ Upstream commit c7e8f404d56b99c80990b19a402c3f640d74be05 ]

The driver's probe() method is written as if platform_get_irq() returns 0
on error, while actually it returns a negative error code (with all the
other values considered valid IRQs). Rewrite the driver's IRQ checking code
to pass the positive IRQ #s to ata_host_activate(), propagate upstream
-EPROBE_DEFER, and set up the driver to polling mode on (negative) errors
and IRQ0 (libata treats IRQ #0 as a polling mode anyway)...

Fixes: a480167b23ef ("pata_arasan_cf: Adding support for arasan compact flash host controller")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/ata/pata_arasan_cf.c b/drivers/ata/pata_arasan_cf.c
index e9cf31f..63f3944 100644 (file)
--- a/drivers/ata/pata_arasan_cf.c
+++ b/drivers/ata/pata_arasan_cf.c
@@ -818,12 +818,19 @@ static int arasan_cf_probe(struct platform_device *pdev)
        else
                quirk = CF_BROKEN_UDMA; /* as it is on spear1340 */
 
-       /* if irq is 0, support only PIO */
-       acdev->irq = platform_get_irq(pdev, 0);
-       if (acdev->irq)
+       /*
+        * If there's an error getting IRQ (or we do get IRQ0),
+        * support only PIO
+        */
+       ret = platform_get_irq(pdev, 0);
+       if (ret > 0) {
+               acdev->irq = ret;
                irq_handler = arasan_cf_interrupt;
-       else
+       } else  if (ret == -EPROBE_DEFER) {
+               return ret;
+       } else  {
                quirk |= CF_BROKEN_MWDMA | CF_BROKEN_UDMA;
+       }
 
        acdev->pbase = res->start;
        acdev->vbase = devm_ioremap(&pdev->dev, res->start,