Patch "drm/i915: Fix scaler init during CRTC HW state readout" has been added to the 4.12-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/i915: Fix scaler init during CRTC HW state readout

to the 4.12-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-scaler-init-during-crtc-hw-state-readout.patch
and it can be found in the queue-4.12 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 283d6860d64f5091565bf729b0a6d6af14ae6c27 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Thu, 20 Jul 2017 14:28:20 +0300
Subject: drm/i915: Fix scaler init during CRTC HW state readout
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Imre Deak <imre.deak@intel.com>

commit 283d6860d64f5091565bf729b0a6d6af14ae6c27 upstream.

The scaler allocation code depends on a non-zero default value for the
crtc scaler_id, so make sure we initialize the scaler state accordingly
even if the crtc is off. This fixes at least an initial YUV420 modeset
(added in a follow-up patchset by Shashank) when booting with the screen
off: after the initial HW readout and modeset which enables the scaler a
subsequent modeset will disable the scaler which isn't properly
allocated. This results in a funky HW state where the pipe scaler HW
registers can't be modified and the normally black screen is grey and
shifted to the right or jitters.

The problem was revealed by Shashank's YUV420 patchset and first
reported by Ville.

v2:
- In the stable tag also include versions which need backporting (Jani)

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chandra Konduru <chandra.konduru@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: a1b2278e4dfc ("drm/i915: skylake panel fitting using shared scalers")
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170720112820.26816-1-imre.deak@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 5fb9dadf336f3590c799e8cbde348215dccc2aa2)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_display.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9085,6 +9085,13 @@ static bool haswell_get_pipe_config(stru
 	u64 power_domain_mask;
 	bool active;
 
+	if (INTEL_GEN(dev_priv) >= 9) {
+		intel_crtc_init_scalers(crtc, pipe_config);
+
+		pipe_config->scaler_state.scaler_id = -1;
+		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
+	}
+
 	power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
 	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
@@ -9113,13 +9120,6 @@ static bool haswell_get_pipe_config(stru
 	pipe_config->gamma_mode =
 		I915_READ(GAMMA_MODE(crtc->pipe)) & GAMMA_MODE_MODE_MASK;
 
-	if (INTEL_GEN(dev_priv) >= 9) {
-		intel_crtc_init_scalers(crtc, pipe_config);
-
-		pipe_config->scaler_state.scaler_id = -1;
-		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
-	}
-
 	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
 	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
 		power_domain_mask |= BIT_ULL(power_domain);


Patches currently in stable-queue which might be from imre.deak@intel.com are

queue-4.12/drm-i915-fix-scaler-init-during-crtc-hw-state-readout.patch