Re: [PATCH] cdx: add MSI support for CDX bus

From: Thomas Gleixner
Date: Tue May 09 2023 - 04:05:23 EST

On Mon, May 08 2023 at 19:39, Nipun Gupta wrote:
> Add CDX-MSI domain with gic-its domain as parent, to support MSI
> for CDX devices. CDX devices allocate MSIs from the CDX domain.
> Also, introduce APIs to alloc and free IRQs for CDX domain.

This lacks any information why this needs to have a separate irq domain
and what this is about. Changelogs need to be self explanatory and
providing a link to some RFC series which might have more information
does not cut it.

Just for the record. I complained about the useless changelog in that
RFC series already.

> Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>
> Signed-off-by: Nikhil Agarwal <nikhil.agarwal@xxxxxxx>
> Signed-off-by: Abhijit Gangurde <abhijit.gangurde@xxxxxxx>

This Signed-off-by chain is broken. If this is intended to denote
co-authorship, then please follow:

> +static struct irq_chip cdx_msi_irq_chip = {
> + .name = "CDX-MSI",
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_set_affinity = msi_domain_set_affinity,
> + .irq_write_msi_msg = cdx_msi_write_msg
> +};

The only real CDX specific functionality here is a CDX specific
irq_write_msi_msg() callback, right?

And I gave you a pointer how this should be handled, but instead of
helping this effort along you go off and implement it differently just
because. Sigh!