From 899d2f9a8b71b424a074eae2746f86c8373a813c Mon Sep 17 00:00:00 2001
From: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Date: Tue, 1 Sep 2020 18:10:36 +0300
Subject: drm/i915: fix regression leading to display audio probe failure on
 GLK
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Git-commit: 0c4c801b31f89cfc1b97207abbab687f43d8e258
Patch-mainline: v5.9-rc5
Alt-commit: cf696856bc54a31f78e6538b84c8f7a006b6108b
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

In commit 4f0b4352bd26 ("drm/i915: Extract cdclk requirements checking
to separate function") the order of force_min_cdclk_changed check and
intel_modeset_checks(), was reversed. This broke the mechanism to
immediately force a new CDCLK minimum, and lead to driver probe
errors for display audio on GLK platform with 5.9-rc1 kernel. Fix
the issue by moving intel_modeset_checks() call later.

[vsyrjala: It also broke the ability of planes to bump up the cdclk
and thus could lead to underruns when eg. flipping from 32bpp to
64bpp framebuffer. To be clear, we still compute the new cdclk
correctly but fail to actually program it to the hardware due to
intel_set_cdclk_{pre,post}_plane_update() not getting called on
account of state->modeset==false.]

Fixes: 4f0b4352bd26 ("drm/i915: Extract cdclk requirements checking to separate function")
BugLink: https://github.com/thesofproject/linux/issues/2410
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200901151036.1312357-1-kai.vehmanen@linux.intel.com
(cherry picked from commit cf696856bc54a31f78e6538b84c8f7a006b6108b)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/display/intel_display.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 68325678f5ef..b18c5ac2934d 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -14956,12 +14956,6 @@ static int intel_atomic_check(struct drm_device *dev,
 	if (dev_priv->wm.distrust_bios_wm)
 		any_ms = true;
 
-	if (any_ms) {
-		ret = intel_modeset_checks(state);
-		if (ret)
-			goto fail;
-	}
-
 	intel_fbc_choose_crtc(dev_priv, state);
 	ret = calc_watermark_data(state);
 	if (ret)
@@ -14976,6 +14970,10 @@ static int intel_atomic_check(struct drm_device *dev,
 		goto fail;
 
 	if (any_ms) {
+		ret = intel_modeset_checks(state);
+		if (ret)
+			goto fail;
+
 		ret = intel_modeset_calc_cdclk(state);
 		if (ret)
 			return ret;
-- 
2.29.2