Hi, On Fri 15 Jan 21, 18:58, Paul Kocialkowski wrote: > A mechanism was recently introduced for the sunxi architecture where > the DMA offset for specific devices (under the MBUS) is set by a common > driver (sunxi_mbus). This driver calls dma_direct_set_offset to set > the device's dma_range_map manually. > > However this information was overwritten by of_dma_configure_id, which > obtains the map from of_dma_get_range (or keeps it NULL when it fails > and the force_dma argument is true, which is the case for platform > devices). > > As a result, the dma_range_map was always overwritten and the mechanism > could not correctly take effect. > > This adds a check to ensure that no previous DMA range map is > overwritten and prints a warning when the map was already set while > also being available from dt. In this case, the map that was already > set is kept. FYI this patch has been superseded by the following: https://patchwork.kernel.org/project/linux-mediatek/patch/20210119105203.15530-1-yong.wu@xxxxxxxxxxxx/ Paul > Fixes: b4bdc4fbf8d0 ("soc: sunxi: Deal with the MBUS DMA offsets in a central place") > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> > --- > drivers/of/device.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/device.c b/drivers/of/device.c > index aedfaaafd3e7..db1b8634c2c7 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -181,7 +181,14 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, > > arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); > > - dev->dma_range_map = map; > + if (!dev->dma_range_map) { > + dev->dma_range_map = map; > + } else if (map) { > + dev_warn(dev, > + "DMA range map was already set, ignoring range map from dt\n"); > + kfree(map); > + } > + > return 0; > } > EXPORT_SYMBOL_GPL(of_dma_configure_id); > -- > 2.30.0 > -- Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com
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