On Fri, Jan 24, 2025 at 12:56:21PM +0200, Jouni Högander wrote:
> We have different approach on how flip is considered being complete. We are
> waiting for vblank on DSB and generate interrupt when it happens and this
> interrupt is considered as indication of completion -> we definitely do not
> want to skip vblank wait.
>
> Also not skipping scanline wait shouldn't cause any problems if we are in
> DEEP_SLEEP PIPEDSL register is returning 0 -> evasion does nothing and if
> we are not in DEEP_SLEEP evasion works same way as without PSR.
>
> Signed-off-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dsb.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
> index 89d3496bcbdbd..bb77ded8bf726 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.c
> @@ -168,13 +168,12 @@ static u32 dsb_chicken(struct intel_atomic_state *state,
> struct intel_crtc *crtc)
> {
IIRC bspec suggests that we should always set DSB_SKIP_WAITS_EN,
so we should probably have a comment here explaining our reason
for omitting it. Otherwise I fear that someone is going to be
blindly reading the spec and then try to add the bit back.
> if (pre_commit_is_vrr_active(state, crtc))
> - return DSB_SKIP_WAITS_EN |
> - DSB_CTRL_WAIT_SAFE_WINDOW |
> + return DSB_CTRL_WAIT_SAFE_WINDOW |
> DSB_CTRL_NO_WAIT_VBLANK |
> DSB_INST_WAIT_SAFE_WINDOW |
> DSB_INST_NO_WAIT_VBLANK;
> else
> - return DSB_SKIP_WAITS_EN;
> + return 0;
> }
>
> static bool assert_dsb_has_room(struct intel_dsb *dsb)
> --
> 2.43.0
--
Ville Syrjälä
Intel
