[Intel-gfx] [PATCH 3/5] drm/i915: Enable fastset for non-boot modesets.

[Maarten Lankhorst]

Now that our state comparison functions are pretty complete, we should
enable fastset by default when a modeset can be avoided. Even if we're
not completely certain about the inherited state, we can be certain
after the first modeset that our sw state matches the hw state.

There is one testcase explicitly testing fastset,
kms_panel_fitting.atomic-fastset but other testcases do so indirectly
because most tests don't clean up the display during exit, or otherwise
indirectly preserve mode by doing igt_display_reset or inheriting during
init.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede at redhat.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 696e6f5680df..f8cbdd50fa38 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11671,6 +11671,11 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
 		(current_config->base.mode.private_flags & I915_MODE_FLAG_INHERITED) &&
 		!(pipe_config->base.mode.private_flags & I915_MODE_FLAG_INHERITED);
 
+	if (fixup_inherited && !i915_modparams.fastboot) {
+		drm_dbg(DRM_UT_KMS, "initial modeset and fastboot not set\n");
+		ret = false;
+	}
+
 #define PIPE_CONF_CHECK_X(name) do { \
 	if (current_config->name != pipe_config->name) { \
 		pipe_config_err(adjust, __stringify(name), \
@@ -12694,8 +12699,7 @@ static int intel_atomic_check(struct drm_device *dev,
 			return ret;
 		}
 
-		if (i915_modparams.fastboot &&
-		    intel_pipe_config_compare(dev_priv,
+		if (intel_pipe_config_compare(dev_priv,
 					to_intel_crtc_state(old_crtc_state),
 					pipe_config, true)) {
 			crtc_state->mode_changed = false;
-- 
2.20.1