[PATCH] dma-mapping: Warn about coherent_dma_mask only for SMP

[Guenter Roeck]

As of commit 205e1b7f51e4 ("dma-mapping: warn when there is no
coherent_dma_mask") is unconditional, even if the affected system
is a single-CPU system where coherence is irrelevant. Limit the
warning to SMP configurations to reduce the noise.

Fixes: 205e1b7f51e4 ("dma-mapping: warn when there is no coherent_dma_mask")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
 include/linux/dma-mapping.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f8ab1c0f589e..ffbb39d84797 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -513,7 +513,7 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 	void *cpu_addr;
 
 	BUG_ON(!ops);
-	WARN_ON_ONCE(dev && !dev->coherent_dma_mask);
+	WARN_ON_ONCE(IS_ENABLED(CONFIG_SMP) && dev && !dev->coherent_dma_mask);
 
 	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
 		return cpu_addr;
-- 
2.7.4