Commit 482bcc7e authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Jani Nikula
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drm/i915/joiner: Make joiner "nomodeset" state copy independent of pipe order 



Currently the joiner primary->secondary hw state copy still happens from
the main compute_config loop alongside the primary uapi->hw state copy.
The primary uapi->hw state copy must therefore happen first, or else
we'll end up copying stale junk into the secondary.

We have a WARN in intel_atomic_check_joiner() to make sure the CRTCs
will be walked in the correct order. The plan is to reoder the CRTCs,
which would mess up the order, unless we also adjust the iterators
to keep the pipe order. The actual plan is to do both, so technically
we should be able to just remove the WARN and call it a day.

But relying on the iteration order like this is fragile and confusing,
so let's move the "nomodeset" joiner state copy into the later loop
where the "modeset" state copy is also done. The first loop having
completely finished, we are guaranteed to have up to date hw state
on the primary when we do the copy to the secondary.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/20260408155744.13326-2-ville.syrjala@linux.intel.com


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 45164322

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

+5 −15
Original line number Diff line number Diff line
@@ -5939,17 +5939,6 @@ static int intel_atomic_check_joiner(struct intel_atomic_state *state, 
			return -EINVAL;

		}



		/*

		 * The state copy logic assumes the primary crtc gets processed

		 * before the secondary crtc during the main compute_config loop.

		 * This works because the crtcs are created in pipe order,

		 * and the hardware requires primary pipe < secondary pipe as well.

		 * Should that change we need to rethink the logic.

		 */

		if (WARN_ON(drm_crtc_index(&primary_crtc->base) >

			    drm_crtc_index(&secondary_crtc->base)))

			return -EINVAL;



		drm_dbg_kms(display->drm,

			    "[CRTC:%d:%s] Used as secondary for joiner primary [CRTC:%d:%s]\n",

			    secondary_crtc->base.base.id, secondary_crtc->base.name,
@@ -6327,9 +6316,7 @@ static int intel_atomic_check_config(struct intel_atomic_state *state, 


	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {

		if (!intel_crtc_needs_modeset(new_crtc_state)) {

			if (intel_crtc_is_joiner_secondary(new_crtc_state))

				copy_joiner_crtc_state_nomodeset(state, crtc);

			else

			if (!intel_crtc_is_joiner_secondary(new_crtc_state))

				intel_crtc_copy_uapi_to_hw_state_nomodeset(state, crtc);

			continue;

		}
@@ -6460,8 +6447,11 @@ int intel_atomic_check(struct drm_device *dev, 
		goto fail;



	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {

		if (!intel_crtc_needs_modeset(new_crtc_state))

		if (!intel_crtc_needs_modeset(new_crtc_state)) {

			if (intel_crtc_is_joiner_secondary(new_crtc_state))

				copy_joiner_crtc_state_nomodeset(state, crtc);

			continue;

		}



		if (intel_crtc_is_joiner_secondary(new_crtc_state)) {

			drm_WARN_ON(display->drm, new_crtc_state->uapi.enable);