[PATCH v2] drm/bridge: tpd12s015: Fix irq registering in tpd12s015_probe

[YueHaibing]

gpiod_to_irq() return negative value in case of error,
the existing code doesn't handle negative error codes.
If the HPD gpio supports IRQs (gpiod_to_irq returns a
valid number), we use the IRQ. If it doesn't (gpiod_to_irq
returns an error), it gets polled via detect(). 

Fixes: cff5e6f7e83f ("drm/bridge: Add driver for the TI TPD12S015 HDMI level shifter")
Signed-off-by: YueHaibing <yuehaibing at huawei.com>
---
v2: Add checking for >= 0 and update commit message
---
 drivers/gpu/drm/bridge/ti-tpd12s015.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ti-tpd12s015.c b/drivers/gpu/drm/bridge/ti-tpd12s015.c
index 514cbf0eac75..e0e015243a60 100644
--- a/drivers/gpu/drm/bridge/ti-tpd12s015.c
+++ b/drivers/gpu/drm/bridge/ti-tpd12s015.c
@@ -160,7 +160,7 @@ static int tpd12s015_probe(struct platform_device *pdev)
 
 	/* Register the IRQ if the HPD GPIO is IRQ-capable. */
 	tpd->hpd_irq = gpiod_to_irq(tpd->hpd_gpio);
-	if (tpd->hpd_irq) {
+	if (tpd->hpd_irq >= 0) {
 		ret = devm_request_threaded_irq(&pdev->dev, tpd->hpd_irq, NULL,
 						tpd12s015_hpd_isr,
 						IRQF_TRIGGER_RISING |
-- 
2.17.1