Re: [PATCH v5 00/15] nova-core: GPU interrupt support and GSP event delivery

[Alexandre Courbot]

On Wed Sep 30, 2026 at 12:41 PM JST, John Hubbard wrote:
> This series adds GPU interrupt support to nova-core, so that GSP events
> reach the driver as interrupts instead of only when the driver polls.
> v5 applies Alex's review of v4, and makes three of the design changes
> that he had set aside for after the merge. The series is 15 patches,
> down from 17. The two rust/ patches are unchanged.
>
> GIN, the GPU Interrupt and Notification unit, is the GPU's interrupt
> controller, and it latches pending interrupts in a two-level register
> tree. TOP, the tree's top-level enable register, holds one enable bit
> per subtree.
>
> The design uses a threaded IRQ handler. The top half reads and writes
> only GPU registers, while the threaded bottom half drains the message
> queue.
>
> Still TODO after this: retrieve the dynamic interrupt routing tables
> from GSP, and use those, instead of the simple, hard-coded approach that
> was done here for these first two interrupts.
>
> The series is based on drm-rust-next at commit 658c5f0042e6 ("gpu:
> nova-core: use a single try_pin_init!() block in probe()"), and it
> carries no prerequisite commits.
>
> The patches, as applied to drm-rust-next, are on a git branch:
>
>     https://github.com/johnhubbard/linux/tree/nova-core-gin-interrupt-tree-v5/

This revision is a quite significant improvement, and although there are
still a few things I want to fix before applying (notably on - guess
what - the HAL :)), this is in the drive-by-upon-apply range. I'll leave
a few review comments for the sake of completeness, but there should be
no need to send a new revision, unless I missed something important on
my first pass.