usb: musb: ux500: Fix NULL pointer dereference at system PM

The commit 7d32cdef5356 ("usb: musb: fail with error when no DMA
controller set"), caused the core platform driver to correctly return an
error code when fail probing.

Unfurtante it also caused bug for a NULL pointer dereference, during
system suspend for the ux500 driver. The reason is a lacking validation
of the corresponding ->driver_data pointer, which won't be set when the
musb core driver fails to probe (or haven't yet been probed).

Fixes: 7d32cdef5356 ("usb: musb: fail with error when no DMA...")
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

diff --git a/drivers/usb/musb/ux500.c b/drivers/usb/musb/ux500.c
index b2685e7..3eaa4ba 100644 (file)
--- a/drivers/usb/musb/ux500.c
+++ b/drivers/usb/musb/ux500.c
@@ -348,7 +348,9 @@ static int ux500_suspend(struct device *dev)
        struct ux500_glue       *glue = dev_get_drvdata(dev);
        struct musb             *musb = glue_to_musb(glue);
 
-       usb_phy_set_suspend(musb->xceiv, 1);
+       if (musb)
+               usb_phy_set_suspend(musb->xceiv, 1);
+
        clk_disable_unprepare(glue->clk);
 
        return 0;
@@ -366,7 +368,8 @@ static int ux500_resume(struct device *dev)
                return ret;
        }
 
-       usb_phy_set_suspend(musb->xceiv, 0);
+       if (musb)
+               usb_phy_set_suspend(musb->xceiv, 0);
 
        return 0;
 }