drm/msm/disp/dpu1: turn off vblank irqs aggressively in dpu driver
Set the flag vblank_disable_immediate = true to turn off vblank irqs
immediately as soon as drm_vblank_put is requested so that there are
no irqs triggered during idle state. This will reduce cpu wakeups
and help in power saving.
To enable vblank_disable_immediate flag the underlying KMS driver
needs to support high precision vblank timestamping and also a
reliable way of providing vblank counter which is incrementing
at the leading edge of vblank.
This patch also brings in changes to support vblank_disable_immediate
requirement in dpu driver.
Changes in v1:
- Specify reason to add vblank timestamp support. (Rob).
- Add changes to provide vblank counter from dpu driver.
Changes in v2:
- Fix warn stack reported by Rob Clark with v2 patch.
Changes in v3:
- Move back to HW frame counter (Rob).
Changes in v4:
- Frame count mismatch was causing a DRM WARN stack spew.
DPU HW will increment the frame count at the end of
the sync, where as vblank will be triggered at the
fetch_start counter which is calculated as v_total - vfp.
This is to start fetching early for panels with low
vbp w.r.t hw latency lines.
Add logic to detect the line count if it falls between
vactive and v_total then return incremented frame count value.
Signed-off-by: Kalyan Thota <kalyan_t@codeaurora.org>
Link: https://lore.kernel.org/r/1613651746-12783-1-git-send-email-kalyan_t@codeaurora.org
Signed-off-by: Rob Clark <robdclark@chromium.org>