Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 26 Dec 2018 08:52:48 -0800 (PST) | Subject | Re: [PATCH] RISC-V: defconfig: Enable Generic PCIE by default | From | Palmer Dabbelt <> |
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On Fri, 21 Dec 2018 11:27:39 PST (-0800), Paul Walmsley wrote: > > On Fri, 21 Dec 2018, Alistair Francis wrote: > >> When the MicroSemi driver does eventually go upstream this will >> probably have to be discussed though as either the config or device >> tree will need to be edited to ensure only one PCIe device is present. > > The right way to do that is to have two separate DT files: one for the > HiFive-U board alone; the other for the HiFive-U plus the expansion board > combo. There shouldn't be any problems with keeping both drivers enabled > in the defconfig.
We actually need at least three:
* One for the HiFive Unleashed * One for the HiFive Unleashed, when attached to the Micro Semi expansion board. * One for the HiFive Unleashed, when attached to a VC707.
We may end up needing additional device trees for the newer Xilinx boards, depending on if it's possible to probe for that 32-bit DMA limit on the VC707 or not. Then, of course, we'll need an image-specific device tree whenever we put an accelerator on the FPGA.
Ideally we'd have a discoverable bus, but that's going to be a bit of a way out. For now we'll have to get by with different device trees, but that should get significantly easier when we get a proper bootloader working.
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