Re: [Qemu-devel] [PATCH] hw/pci: add pci capability to pci-pci bridge

[Liu, Jing2]

On 8/14/2018 9:27 PM, Laszlo Ersek wrote:
[...]
> > > >    +cap_error:
> > > > +    msi_uninit(dev);
> > >
> > > (4) This error handler doesn't look entirely correct; we can reach it
> > > without having initialized MSI. (MSI setup is conditional; and even if
> > > we attempt it, it is permitted to fail with "msi=auto".) Therefore,
> > > msi_uninit() should be wrapped into "if (msi_present())", same as you
> > > see in pci_bridge_dev_exitfn().
> >
> > sure, can add a pre-check. But I don't understand why we need that,
> > msi_uninit() will check msi_present()?
>
> Thanks for pointing that out.
>
> So, I grepped the source code for msi_uninit(). It seems that only one
> location gates it with msi_present() -- in pci_bridge_dev_exitfn() --,
> while 13 other locations just call it unconditionally.
>
> I don't know what the consistent approach is here. I'll have to defer to
> the PCI maintainers; their taste will decide. Technically your code
> looks correct, then.
Yes, I also grep that. I guess if we directly use msi_uninit, this is 
because msi_init is non-conditional too.
Anyway, I added check in my version two. BTW, other comments are 
included in v2.

Thanks,
Jing

> Thanks
> Laszlo