spi: core: Fix check for dma_map_sg() failures

According to Documentation/DMA-API.txt, dma_map_sg() returns 0 on failure.
As spi_map_buf() returns an error code, convert zero into -ENOMEM.
Keep the existing check for negative numbers just in case.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index d4f9670b51bc..91bb512e1009 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -619,6 +619,8 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
         }
 
         ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
+        if (!ret)
+                ret = -ENOMEM;
         if (ret < 0) {
                 sg_free_table(sgt);
                 return ret;