mtd: rawnand: atmel: Fix potential NULL pointer dereference

[mirror_ubuntu-bionic-kernel.git] / drivers / mtd / nand / atmel / nand-controller.c

diff --git a/drivers/mtd/nand/atmel/nand-controller.c b/drivers/mtd/nand/atmel/nand-controller.c
index 90a71a56bc230f9cc3324d2351f9d6bfc9667254..1d9a096fca655693143f67626139b79607bfae85 100644 (file)
--- a/drivers/mtd/nand/atmel/nand-controller.c
+++ b/drivers/mtd/nand/atmel/nand-controller.c
@@ -129,6 +129,11 @@
 #define DEFAULT_TIMEOUT_MS                     1000
 #define MIN_DMA_LEN                            128
 
+static bool atmel_nand_avoid_dma __read_mostly;
+
+MODULE_PARM_DESC(avoiddma, "Avoid using DMA");
+module_param_named(avoiddma, atmel_nand_avoid_dma, bool, 0400);
+
 enum atmel_nand_rb_type {
        ATMEL_NAND_NO_RB,
        ATMEL_NAND_NATIVE_RB,
@@ -1974,7 +1979,7 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc,
                return ret;
        }
 
-       if (nc->caps->has_dma) {
+       if (nc->caps->has_dma && !atmel_nand_avoid_dma) {
                dma_cap_mask_t mask;
 
                dma_cap_zero(mask);
@@ -2073,6 +2078,10 @@ atmel_hsmc_nand_controller_legacy_init(struct atmel_hsmc_nand_controller *nc)
        nand_np = dev->of_node;
        nfc_np = of_find_compatible_node(dev->of_node, NULL,
                                         "atmel,sama5d3-nfc");
+       if (!nfc_np) {
+               dev_err(dev, "Could not find device node for sama5d3-nfc\n");
+               return -ENODEV;
+       }
 
        nc->clk = of_clk_get(nfc_np, 0);
        if (IS_ERR(nc->clk)) {