[PATCH] dmaengine: tegra210-adma: fix of_irq_get() error check

[Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>]

[-- Attachment #1: dmaengine-tegra210-adma-fix-of_irq_get-error-check.patch --]
[-- Type: text/plain, Size: 1127 bytes --]

of_irq_get() may return 0 as well as negative error number on failure,
while the driver only checks for the negative values. The driver would then
call request_irq(0, ...) in tegra_adma_alloc_chan_resources() and never get
valid channel interrupt.

Check for 'tdc->irq <= 0' instead and return -ENXIO from the driver's probe
iff of_irq_get() returned 0.

Fixes: f46b195799b5 ("dmaengine: tegra-adma: Add support for Tegra210 ADMA")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>

---
 drivers/dma/tegra210-adma.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: slave-dma/drivers/dma/tegra210-adma.c
===================================================================
--- slave-dma.orig/drivers/dma/tegra210-adma.c
+++ slave-dma/drivers/dma/tegra210-adma.c
@@ -717,8 +717,8 @@ static int tegra_adma_probe(struct platf
 		tdc->chan_addr = tdma->base_addr + ADMA_CH_REG_OFFSET(i);
 
 		tdc->irq = of_irq_get(pdev->dev.of_node, i);
-		if (tdc->irq < 0) {
-			ret = tdc->irq;
+		if (tdc->irq <= 0) {
+			ret = tdc->irq ?: -ENXIO;
 			goto irq_dispose;
 		}