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>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index d4f9670..91bb512 100644 (file)
--- 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;