[PATCH v3] spi: tegra20: Fix missing IRQ check in tegra_slink_probe

[Miaoqian Lin <linmq006@gmail.com>]

This func misses checking for platform_get_irq()'s call and may passes the
negative error codes to request_threaded_irq(), which takes unsigned IRQ #,
causing it to fail with -EINVAL, overriding an original error code.
Stop calling request_threaded_irq() with invalid IRQ #s.

Fixes: dc4dc3605639 ("spi: tegra: add spi driver for SLINK controller")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
Changes in v2:
- fix wrong func name in commit message.
Changes in v3:
- fix Fixes tag info.
- remove redundant error message.
---
 drivers/spi/spi-tegra20-slink.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c
index 2a03739a0c60..f8661963ecba 100644
--- a/drivers/spi/spi-tegra20-slink.c
+++ b/drivers/spi/spi-tegra20-slink.c
@@ -1100,6 +1100,10 @@ static int tegra_slink_probe(struct platform_device *pdev)
 	reset_control_deassert(tspi->rst);
 
 	spi_irq = platform_get_irq(pdev, 0);
+	if (spi_irq < 0) {
+		ret = spi_irq;
+		goto exit_pm_put;
+	}
 	tspi->irq = spi_irq;
 	ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
 				   tegra_slink_isr_thread, IRQF_ONESHOT,
-- 
2.17.1