drm/nouveau/gsp/r570: Add support for INTERNAL_GCX_ENTRY_PREREQUISITE

OpenRM's runtime PM handling looks a bit different then nouveau's, one part
in particular that differs from us: OpenRM actually consults GSP to ask
whether the GPU should be allowed to enter Gc6 and/or GcOff before runtime
suspending the GPU. In the event the card isn't ready, runtime suspend is
simply delayed for a few seconds before retrying.

Implement the command used for querying GSP about this,
NV2080_CTRL_CMD_INTERNAL_GCX_ENTRY_PREREQUISITE, and check to ensure that
the GPU is ready for runtime suspend in nouveau_pmops_runtime_suspend()
using this query. If the GPU can't be runtime suspended, update the last
busy counter of the device and then return -EBUSY from
nouveau_pmops_runtime_suspend() - essentially delaying the runtime suspend
process by whatever autosuspend_delay_ms is set to.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260917185916.1089621-2-lyude@redhat.com
This commit is contained in:
Lyude Paul 2026-09-17 14:54:25 -04:00
commit cb4c760367
11 changed files with 122 additions and 0 deletions