4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 6778be4e520959659b27a441c06a84c9cb009085 ]
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@iki.fi Reported-by: Jean-Philippe Brucker jean-philippe.brucker@arm.com Tested-by: Aaro Koskinen aaro.koskinen@iki.fi Tested-by: John Stultz john.stultz@linaro.org Tested-by: Geert Uytterhoeven geert+renesas@glider.be Tested-by: Robert Richter robert.richter@cavium.com Signed-off-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5957cd4fa262..40b9051a7fce 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",