Re: [RFC V1 1/7] genirq/msi: Differentiate between various MSI based interrupts

[Jason Gunthorpe]

On Thu, Sep 12, 2019 at 06:32:02PM -0700, Megha Dey wrote:
> Since a device can support both MSI-X and IMS interrupts simultaneously,
> do away with is_msix and introduce a new enum msi_desc_tag to
> differentiate between the various types of msi_descs.

It would be clearer if this commit message explaind that this is a
cleanup creating a normal tagged union:

struct msi_desc {
 [..]
        union {
        
Where the tag says which of the elements in the union is filled in

> +enum msi_desc_tags {
> +	IRQ_MSI_TAG_MSI,
> +	IRQ_MSI_TAG_MSIX,
> +	IRQ_MSI_TAG_IMS,

And don't add IMS to the enum until you add a IMS member to the union.

Jason