Re: [Qemu-devel] [PATCH] hw/riscv/virt: re-add machine-specific compatible string to /soc/ node

[Bin Meng]

Hi Lukas,

On Sun, Mar 10, 2019 at 9:44 PM Auer, Lukas
<address@hidden> wrote:
>
> Hi Bin,
>
> On Sun, 2019-03-10 at 09:07 +0800, Bin Meng wrote:
> > Hi Lukas,
> >
> > On Mon, Feb 11, 2019 at 6:13 AM Lukas Auer
> > <address@hidden> wrote:
> > > Re-add the previous compatible string "riscv-virtio-soc" to the soc
> > > device tree node to allow U-Boot and Linux to bind machine-specific
> > > drivers to it. The current compatible string "simple-bus" is
> > > retained.
> > >
> > > This is required by U-Boot to bind devices early, as part of the
> > > pre-relocation driver model.
> > >
> >
> > I see no problem with U-Boot working with current compatible string
> > "simple-bus". In fact I had planned to remove the compatible string
> > "riscv-virtio-soc" in U-Boot but did not get time to work on it.
> >
>
> It is only required if U-Boot is running in machine-mode. For
> relocation it needs to use the CLINT driver to send appropriate IPIs to
> the other harts. To be able to probe the driver, the device and its
> parent device tree node (soc) must therefore be available in the pre-
> relocation device model.
> This patch was the easiest way I could think of for achieving this. It
> could be that there is a better way of solving this.
>

I tested your SMP U-Boot series in both M-mode and S-mode, using a 4
core 'virt' target. Works fine. I am using QEMU 3.1.0 so it is
"simple-bus".

Regards,
Bin