Ugh, interrupt mappings. This is one of the reasons i like petalinux, because this is handled for you automatically when you import your .hdf.
Assuming your mm2s interrupt is connected to In0 of the interrupt concat block and the s2mm interrupt is connected to In1, your channel interrupts look good. I think you can get rid of the interrupts property in the parent DMA node that attempts to map both of them, according to: https://github.com/Digilent/linux-digilent/blob/master/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt.
I'm not familiar with the DMA test driver, but in these situations I typically would dig around in the dma and dmatest probe functions to see what is triggering the kernel msg you posted. Then go from there, and maybe add additional printk's to the drivers if you need them. Depending on your kernel version, the Xilinx DMA driver just may not work with the dma test driver. The driver code for the Xilinx DMA has proven to be very volatile over the years, and I remember previous cases of people not being able to get the test driver to work. You might want to try fishing around the xilinx kernel tree and see if anything has been done in regards to this recently.