Re: [PATCH V7 3/4] PCI: vmd: Add vmd_device_data

[Christoph Hellwig]

On Fri, Oct 28, 2022 at 02:13:08PM -0500, Bjorn Helgaas wrote:
> It looks like these devices come in families where several device IDs
> share the same features.  I think this would be more readable if you
> defined each family outside this table and simply referenced the
> family here.  E.g., you could do something like:
> 
>   static struct vmd_device_data vmd_v1 = {
>     .features = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
> 		VMD_FEAT_HAS_BUS_RESTRICTIONS |
> 		VMD_FEAT_OFFSET_FIRST_VECTOR,
>   };
> 
>   {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
>     .driver_data = (kernel_ulong_t) &vmd_v1,
> 
> Then you can add VMD_FEAT_BIOS_PM_QUIRK and the .ltr value in one place
> instead of repeating it a half dozen times.

I wonder why we need the ltr field at all.  For those that set it
is always the same value, so it could just be a quirk flag to set it.

Tat being said I think thegrouping makes a lot of sense, but I'd just
do it with a #define for the set of common quirk flags.