From: Frank Rowand <frank.rowand@xxxxxxxxxxxxxx> This is a somewhat scary patch since it touches a path that is central to device creation based on the device tree. It should not be applied without careful consideration. I am not sure if this patch is a good idea, even if it does not break anything. An issue with the path of SPMI nodes under /sys/bus/... was reported in https://lkml.org/lkml/2014/4/23/312. The symptom is that two different grandchild nodes of the spmi with the same node-name@unit-address will result in attempting to create duplicate links at /sys/bus/platform/devices/unit-address.node-name. It turns out that the specific example provided might not be an expected configuration for current hardware, but the reported trap remains an issue. The common pattern exposed is a driver probe function calling of_platform_populate() to create child devices. As the reporting email noted, the devices are created with dev.bus set to platform_bus_type. Thus all devices created via this pattern will result in a link in /sys/bus/platform/devices/, with the risk that a name collision will occur. This patch reduces the scope of possible name collisions to devices on the same bus type. This is still not ideal, because a legal device tree source file can result in run time errors. In the case of SPMI nodes, the collisions will occur in /bus/spmi/devices/. I have not investigated whether other drivers would be negatively impacted by this change - there are 26 drivers in tree that call of_platform_populate(). Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxxxxxxxx> --- drivers/of/platform.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) Index: b/drivers/of/platform.c =================================================================== --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -217,7 +217,10 @@ static struct platform_device *of_platfo dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); if (!dev->dev.dma_mask) dev->dev.dma_mask = &dev->dev.coherent_dma_mask; - dev->dev.bus = &platform_bus_type; + if (parent && parent->bus) + dev->dev.bus = parent->bus; + else + dev->dev.bus = &platform_bus_type; dev->dev.platform_data = platform_data; /* We do not fill the DMA ops for platform devices by default. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
