mmc: mtk-sd: check for valid optional memory resource

'top_base' memory region is optional. Check that the resource is valid
before using it. This avoid getting a "invalid resource" error message
printed by the kernel.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index bd731bd..0798f0b 100644 (file)
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -2134,9 +2134,11 @@ static int msdc_drv_probe(struct platform_device *pdev)
        }
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-       host->top_base = devm_ioremap_resource(&pdev->dev, res);
-       if (IS_ERR(host->top_base))
-               host->top_base = NULL;
+       if (res) {
+               host->top_base = devm_ioremap_resource(&pdev->dev, res);
+               if (IS_ERR(host->top_base))
+                       host->top_base = NULL;
+       }
 
        ret = mmc_regulator_get_supply(mmc);
        if (ret)