[PATCH] usb: dwc3: leave default DMA for PCI devices

[Fabio Aiuto <fabioaiuto83@gmail.com>]

in case of a PCI dwc3 controller, leave the default DMA
mask. Calling of a 64 bit DMA mask breaks the driver on
cherrytrail based tablets like Cyberbook T116.

Fixes: 45d39448b4d0 ("usb: dwc3: support 64 bit DMA in platform driver")
Reported-by: Hans De Goede <hdegoede@redhat.com>
Tested-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
---
 drivers/usb/dwc3/core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 643239d7d370..f4c09951b517 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1594,9 +1594,11 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	dwc3_get_properties(dwc);
 
-	ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
-	if (ret)
-		return ret;
+	if (!dwc->sysdev_is_parent) {
+		ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
+		if (ret)
+			return ret;
+	}
 
 	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
 	if (IS_ERR(dwc->reset))
-- 
2.30.2