drm/tegra: falcon: Fix error handling

The ->alloc() callback in struct falcon_ops returns an ERR_PTR()-encoded
error code on failure, so it needs to be properly checked for, otherwise
subsequent code may dereference an invalid pointer.

Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/tegra/falcon.c b/drivers/gpu/drm/tegra/falcon.c
index f685e72..78c7a01 100644 (file)
--- a/drivers/gpu/drm/tegra/falcon.c
+++ b/drivers/gpu/drm/tegra/falcon.c
@@ -141,9 +141,9 @@ int falcon_load_firmware(struct falcon *falcon)
        /* allocate iova space for the firmware */
        falcon->firmware.vaddr = falcon->ops->alloc(falcon, firmware->size,
                                                    &falcon->firmware.paddr);
-       if (!falcon->firmware.vaddr) {
-               dev_err(falcon->dev, "dma memory mapping failed\n");
-               return -ENOMEM;
+       if (IS_ERR(falcon->firmware.vaddr)) {
+               dev_err(falcon->dev, "DMA memory mapping failed\n");
+               return PTR_ERR(falcon->firmware.vaddr);
        }
 
        /* copy firmware image into local area. this also ensures endianness */