Patch "drm/i915: Fix watermarks for VLV/CHV" has been added to the 4.6-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/i915: Fix watermarks for VLV/CHV

to the 4.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-fix-watermarks-for-vlv-chv.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From caed361d83b204b7766924b80463bf7502ee7986 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Wed, 9 Mar 2016 19:07:25 +0200
Subject: drm/i915: Fix watermarks for VLV/CHV
MIME-Version: 1.0
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From: Ville Syrjälä <ville.syrjala@linux.intel.com>

commit caed361d83b204b7766924b80463bf7502ee7986 upstream.

commit 92826fcdfc14 ("drm/i915: Calculate watermark related members in the crtc_state, v4.")
broke thigns by removing the pre vs. post wm update distinction. We also
lost the pre plane wm update entirely for VLV/CHV from the crtc enable
path.

This caused underruns on modeset and plane enable/disable on CHV,
and often those can lead to a dead pipe.

So let's bring back the pre vs. post thing, and let's toss in an
explicit wm update to valleyview_crtc_enable() to avoid having to
put it into the common code.

This is more or less a partial revert of the offending commit.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 92826fcdfc14 ("drm/i915: Calculate watermark related members in the crtc_state, v4.")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457543247-13987-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_atomic.c  |    3 ++-
 drivers/gpu/drm/i915/intel_display.c |   25 +++++++++++++++++--------
 drivers/gpu/drm/i915/intel_drv.h     |    2 +-
 3 files changed, 20 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/i915/intel_atomic.c
+++ b/drivers/gpu/drm/i915/intel_atomic.c
@@ -96,7 +96,8 @@ intel_crtc_duplicate_state(struct drm_cr
 	crtc_state->update_pipe = false;
 	crtc_state->disable_lp_wm = false;
 	crtc_state->disable_cxsr = false;
-	crtc_state->wm_changed = false;
+	crtc_state->update_wm_pre = false;
+	crtc_state->update_wm_post = false;
 	crtc_state->fb_changed = false;
 
 	return &crtc_state->base;
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4796,7 +4796,7 @@ static void intel_post_plane_update(stru
 
 	crtc->wm.cxsr_allowed = true;
 
-	if (pipe_config->wm_changed && pipe_config->base.active)
+	if (pipe_config->update_wm_post && pipe_config->base.active)
 		intel_update_watermarks(&crtc->base);
 
 	if (atomic->update_fbc)
@@ -4843,7 +4843,7 @@ static void intel_pre_plane_update(struc
 			intel_set_memory_cxsr(dev_priv, false);
 	}
 
-	if (!needs_modeset(&pipe_config->base) && pipe_config->wm_changed)
+	if (!needs_modeset(&pipe_config->base) && pipe_config->update_wm_pre)
 		intel_update_watermarks(&crtc->base);
 }
 
@@ -6210,6 +6210,7 @@ static void valleyview_crtc_enable(struc
 
 	intel_crtc_load_lut(crtc);
 
+	intel_update_watermarks(crtc);
 	intel_enable_pipe(intel_crtc);
 
 	assert_vblank_disabled(crtc);
@@ -11833,14 +11834,22 @@ int intel_plane_atomic_calc_changes(stru
 			 plane->base.id, was_visible, visible,
 			 turn_off, turn_on, mode_changed);
 
-	if (turn_on || turn_off) {
-		pipe_config->wm_changed = true;
+	if (turn_on) {
+		pipe_config->update_wm_pre = true;
+
+		/* must disable cxsr around plane enable/disable */
+		if (plane->type != DRM_PLANE_TYPE_CURSOR)
+			pipe_config->disable_cxsr = true;
+	} else if (turn_off) {
+		pipe_config->update_wm_post = true;
 
 		/* must disable cxsr around plane enable/disable */
 		if (plane->type != DRM_PLANE_TYPE_CURSOR)
 			pipe_config->disable_cxsr = true;
 	} else if (intel_wm_need_update(plane, plane_state)) {
-		pipe_config->wm_changed = true;
+		/* FIXME bollocks */
+		pipe_config->update_wm_pre = true;
+		pipe_config->update_wm_post = true;
 	}
 
 	if (visible || was_visible)
@@ -11940,7 +11949,7 @@ static int intel_crtc_atomic_check(struc
 	}
 
 	if (mode_changed && !crtc_state->active)
-		pipe_config->wm_changed = true;
+		pipe_config->update_wm_post = true;
 
 	if (mode_changed && crtc_state->enable &&
 	    dev_priv->display.crtc_compute_clock &&
@@ -13453,12 +13462,12 @@ static bool needs_vblank_wait(struct int
 		return true;
 
 	/* wm changes, need vblank before final wm's */
-	if (crtc_state->wm_changed)
+	if (crtc_state->update_wm_post)
 		return true;
 
 	/*
 	 * cxsr is re-enabled after vblank.
-	 * This is already handled by crtc_state->wm_changed,
+	 * This is already handled by crtc_state->update_wm_post,
 	 * but added for clarity.
 	 */
 	if (crtc_state->disable_cxsr)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -379,7 +379,7 @@ struct intel_crtc_state {
 
 	bool update_pipe; /* can a fast modeset be performed? */
 	bool disable_cxsr;
-	bool wm_changed; /* watermarks are updated */
+	bool update_wm_pre, update_wm_post; /* watermarks are updated */
 	bool fb_changed; /* fb on any of the planes is changed */
 
 	/* Pipe source size (ie. panel fitter input size)


Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are

queue-4.6/drm-i915-fix-watermarks-for-vlv-chv.patch
queue-4.6/drm-i915-psr-try-to-program-link-training-times-correctly.patch
queue-4.6/mfd-intel_soc_pmic_core-terminate-panel-control-gpio-lookup-table-correctly.patch
queue-4.6/drm-add-helper-for-dp-adaptors.patch
queue-4.6/drm-i915-don-t-leave-old-junk-in-ilk-active-watermarks-on-readout.patch
queue-4.6/drm-i915-enable-disable-tmds-output-buffers-in-dp-adaptor-as-needed.patch
queue-4.6/drm-i915-pass-the-correct-crtc-state-to-.update_plane.patch
queue-4.6/drm-i915-respect-dp-adaptor-tmds-clock-limit.patch