of_dma_configure() was *supposed* to be following the same logic as
acpi_dma_configure() and only setting bus_dma_mask if some range was
specified by the firmware. However, it seems that subtlety got lost in
the process of fitting it into the differently-shaped control flow, and
as a result the force_dma==true case ends up always setting the bus mask
to the 32-bit default, which is not what anyone wants.
Make sure we only touch it if the DT actually said so.
Fixes: 6c2fb2ea7636 ("of/device: Set bus DMA mask as appropriate")
Reported-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
Reported-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
Tested-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
Tested-by: John Stultz <john.stultz@xxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Robert Richter <robert.richter@xxxxxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
v2: Add comment, collect tested-by tags
drivers/of/device.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 0f27fad9fe94..5592437bb3d1 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -149,9 +149,11 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
* set by the driver.
*/
mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
- dev->bus_dma_mask = mask;
dev->coherent_dma_mask &= mask;
*dev->dma_mask &= mask;
+ /* ...but only set bus mask if we found valid dma-ranges earlier */
+ if (!ret)
+ dev->bus_dma_mask = mask;
coherent = of_dma_is_coherent(np);
dev_dbg(dev, "device is%sdma coherent\n",
--
2.19.1.dirty
