spi: rspi: Fix NULL pointer dereference on SH7757

SH7757 doesn't pass platform data, in which case spi-rspi uses default
parameters.

However, commit 5ce0ba88650f2606244a761d92e2b725f4ab3583 ("spi: rcar: add
Renesas QSPI support on RSPI") added a new user of the platform data, but
forgot to check for its validity first, causing a NULL pointer dereference
on SH7757.

Add the missing check to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 58449ad..b60862f 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -958,8 +958,9 @@ static int rspi_probe(struct platform_device *pdev)
        INIT_WORK(&rspi->ws, rspi_work);
        init_waitqueue_head(&rspi->wait);
 
-       master->num_chipselect = rspi_pd->num_chipselect;
-       if (!master->num_chipselect)
+       if (rspi_pd && rspi_pd->num_chipselect)
+               master->num_chipselect = rspi_pd->num_chipselect;
+       else
                master->num_chipselect = 2; /* default */
 
        master->bus_num = pdev->id;