[PATCH] qemu: arm: Scan the pci bus in board_init

[Heinrich Schuchardt]

On 12/31/19 4:49 PM, Sughosh Ganu wrote:
>
> On Tue, 31 Dec 2019 at 20:38, Heinrich Schuchardt <xypron.glpk at gmx.de
> <mailto:xypron.glpk at gmx.de>> wrote:
>
>     On 12/31/19 2:31 PM, Sughosh Ganu wrote:
>      > Scan the pci bus in board_init routine before scanning the virtio
>      > devices. This enumerates all the virtio devices, including devices
>      > found on the pci bus.
>      >
>      > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org
>     <mailto:sughosh.ganu at linaro.org>>
>      > ---
>      >  board/emulation/qemu-arm/qemu-arm.c | 7 +++++++
>      >  1 file changed, 7 insertions(+)
>      >
>      > diff --git a/board/emulation/qemu-arm/qemu-arm.c
>     b/board/emulation/qemu-arm/qemu-arm.c
>      > index 4e18733..6c5335c 100644
>      > --- a/board/emulation/qemu-arm/qemu-arm.c
>      > +++ b/board/emulation/qemu-arm/qemu-arm.c
>      > @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
>      >  int board_init(void)
>      >  {
>      >       /*
>      > +      * Scan the pci bus before calling virtio_init. This
>      > +      * enumerates all virtio devices, including devices
>      > +      * on the pci bus.
>
>     The last sentence is easy to misunderstand. You surely do not mean that
>     pci_init() would enumerate all virtio devices including mmio virtio
>     devices.
>
>     I would suggest to rephrase it to "This enumerates all pci devices
>     including virtio devices on the pci bus."
>
>
> Ok.
>
>
>     With the patch I no longer need to run `virtio scan` on
>     qemu_arm64_defonfig before using the rng command supplied in patch
>
>     [PATCH 1/1] cmd: add rng command
>     https://lists.denx.de/pipermail/u-boot/2019-December/394539.html
>
>     Unfortunately you only considered the ARM architecture. We need a
>     solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).
>
>
> That is fine with me, but currently, only risc-v and arm architectures
> are calling virtio_init.
>
>
>     How about eliminating board_init() for ARM and RISC-V and moving
>     virtio_init() to common/board_r.c after initr_pci?
>
>
> That can be done, but currently, for some reason, initr_pci function
> calls pci_init only when CONFIG_DM_PCI is not defined. Not sure why that
> is the case, although initr_pci gets called after initr_dm.
>
> -sughosh

This dates back to Simon's commit ff3e077bd23c ("dm: pci: Add a uclass
for PCI").

I hope that Simon can tell us why he chose not to call pci_init() if
DM_PCI is defined.

Best regards

Heinrich