Re: [RFC PATCH 6/6] hw/arm/cubieboard: Disable unsupported M-USB in device tree blob

[Peter Maydell]

On Mon, 30 Dec 2019 at 11:10, Philippe Mathieu-Daudé <address@hidden> wrote:
>
> We do not model the Sunxi Multipoint USB.
> The Linux kernel OOPS when booting:

> This is not critical but confusing. To avoid the Linux kernel to
> probe this device, mark it disabled in the device tree blob.
>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> ---
> I'm not sure if this is a QEMU anti-pattern or bad practice.
> I know we prefer to be as close to the hardware as possible,
> but here the hardware is not changed, the dtb is. However
> this makes the guest behave differently. At least we don't
> have to manually edit the dts. If this is only annoying for
> acceptance testing, we might consider manually editing the
> dts in the tests setup().

In general I'd definitely prefer it if we avoided editing
the DTB for things like this (we have very few boards that
edit the DTB and none of them do it as workarounds for
buggy/missing device emulation). Is it possible to have
at least a dummy implementation of the controller that's
enough to make the probe function fail more cleanly?

thanks
-- PMM