Commit 44378f6e authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/dsb: Clear DSB_ENABLE_DEWAKE once the DSB is done 



In order to avoid the DSB keeping the DEwake permanently
asserted we must clear DSB_PMCTRL_2.DSB_FORCE_DEWAKE once
we are done. For good measure do the same for
DSB_PMCTRL.DSB_ENABLE_DEWAKE.

Experimentally this doens't seem to be actually necessary
(unlike with DSB_FORCE_DEWAKE). That is, the DSB_ENABLE_DEWAKE
doesn't seem to do anything whenever the DSB is not active.
But I'd hate to waste a ton of power in case there I'm wrong
and there is some way DEwake could remaing asserted. One extra
register write is a small price to pay for some peace of mind.

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624191032.27333-13-ville.syrjala@linux.intel.com


Reviewed-by: default avatarAnimesh Manna <animesh.manna@intel.com>
parent 51e03954

drivers/gpu/drm/i915/display/intel_dsb.c

+3 −1
Original line number Diff line number Diff line
@@ -464,8 +464,10 @@ void intel_dsb_finish(struct intel_dsb *dsb) 
	/*

	 * DSB_FORCE_DEWAKE remains active even after DSB is

	 * disabled, so make sure to clear it (if set during

	 * intel_dsb_commit()).

	 * intel_dsb_commit()). And clear DSB_ENABLE_DEWAKE as

	 * well for good measure.

	 */

	intel_dsb_reg_write(dsb, DSB_PMCTRL(crtc->pipe, dsb->id), 0);

	intel_dsb_reg_write_masked(dsb, DSB_PMCTRL_2(crtc->pipe, dsb->id),

				   DSB_FORCE_DEWAKE, 0);