On 25/11/2020 15:54, Marc Zyngier wrote:

On 2020-11-25 14:09, Laurent Vivier wrote:

quoted

On 25/11/2020 14:20, Thomas Gleixner wrote:

quoted

Laurent,

On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:

The proper subsystem prefix is: 'genirq/irqdomain:' and the first letter
after the colon wants to be uppercase.

Ok.

quoted

quoted

This function adds an affinity parameter to irq_create_mapping().
This parameter is needed to pass it to irq_domain_alloc_descs().

A changelog has to explain the WHY. 'The parameter is needed' is not
really useful information.

The reason of this change is explained in PATCH 2.

I have two patches, one to change the interface with no functional
change (PATCH 1) and
one to fix the problem (PATCH 2). Moreover they don't cover the same subsystems.

I can either:
- merge the two patches
- or make a reference in the changelog of PATCH 1 to PATCH 2
  (something like "(see folowing patch "powerpc/pseries: pass MSI affinity to
   irq_create_mapping()")")
- or copy some information from PATCH 2
  (something like "this parameter is needed by rtas_setup_msi_irqs()
to pass the affinity
   to irq_domain_alloc_descs() to fix multiqueue affinity")

What do you prefer?

How about something like this for the first patch:

"There is currently no way to convey the affinity of an interrupt
 via irq_create_mapping(), which creates issues for devices that
 expect that affinity to be managed by the kernel.

 In order to sort this out, rename irq_create_mapping() to
 irq_create_mapping_affinity() with an additional affinity parameter
 that can conveniently passed down to irq_domain_alloc_descs().

 irq_create_mapping() is then re-implemented as a wrapper around
 irq_create_mapping_affinity()."

It looks perfect. I update the changelog with that.

Thanks,
Laurent