On Tue, May 23, 2017 at 9:24 AM, Krzysztof Kozlowski [off-list ref] wrote:

On Tue, May 23, 2017 at 2:25 AM, Gustavo A. R. Silva
[off-list ref] wrote:

quoted

Add null check before dereferencing pointer desc

Addresses-Coverity-ID: 1397997
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 drivers/spi/spi-s3c64xx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index b392cca..9f1013e 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c

@@ -306,6 +306,12 @@ static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
        desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
                                       dma->direction, DMA_PREP_INTERRUPT);

+       if (!desc) {
+               dev_err(&sdd->master->dev,
+                       "%s:dmaengine_prep_slave_sg Failed\n", __func__);
+               return;
+       }

Although the check itself looks needed, but I think you did not handle
the error at all. You just bail out before submitting dma descriptor
but except that, everything else goes like there was no error. It
might work, might not... did you test this error path? How does it
behave?

I.e. does it fall back to PIO?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

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when I'm talking to journalists I just say "programmer" or something like that.
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