Patch "drm/i915/lspcon: Fix resume time initialization due to unasserted HPD" has been added to the 4.10-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/i915/lspcon: Fix resume time initialization due to unasserted HPD

to the 4.10-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-lspcon-fix-resume-time-initialization-due-to-unasserted-hpd.patch
and it can be found in the queue-4.10 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 4b84b4a5507913ee0da27b1f1b27671937839de6 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Fri, 27 Jan 2017 11:39:19 +0200
Subject: drm/i915/lspcon: Fix resume time initialization due to unasserted HPD
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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

commit 4b84b4a5507913ee0da27b1f1b27671937839de6 upstream.

During system resume time initialization the HPD level on LSPCON ports
can stay low for an extended amount of time, leading to failed AUX
transfers and LSPCON initialization. Fix this by waiting for HPD to get
asserted.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485509961-9010-3-git-send-email-imre.deak@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
(corrected stable tag)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_dp.c     |    4 ++--
 drivers/gpu/drm/i915/intel_drv.h    |    2 ++
 drivers/gpu/drm/i915/intel_lspcon.c |    5 ++++-
 3 files changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4289,8 +4289,8 @@ static bool bxt_digital_port_connected(s
  *
  * Return %true if @port is connected, %false otherwise.
  */
-static bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
-					 struct intel_digital_port *port)
+bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
+				  struct intel_digital_port *port)
 {
 	if (HAS_PCH_IBX(dev_priv))
 		return ibx_digital_port_connected(dev_priv, port);
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1451,6 +1451,8 @@ bool intel_dp_read_dpcd(struct intel_dp
 bool __intel_dp_read_desc(struct intel_dp *intel_dp,
 			  struct intel_dp_desc *desc);
 bool intel_dp_read_desc(struct intel_dp *intel_dp);
+bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
+				  struct intel_digital_port *port);
 
 /* intel_dp_aux_backlight.c */
 int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector);
--- a/drivers/gpu/drm/i915/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -100,6 +100,8 @@ static bool lspcon_probe(struct intel_ls
 static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon)
 {
 	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
 	unsigned long start = jiffies;
 
 	if (!lspcon->desc_valid)
@@ -115,7 +117,8 @@ static void lspcon_resume_in_pcon_wa(str
 		if (!__intel_dp_read_desc(intel_dp, &desc))
 			return;
 
-		if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) {
+		if (intel_digital_port_connected(dev_priv, dig_port) &&
+		    !memcmp(&intel_dp->desc, &desc, sizeof(desc))) {
 			DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n",
 				      jiffies_to_msecs(jiffies - start));
 			return;


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

queue-4.10/drm-i915-lspcon-fix-resume-time-initialization-due-to-unasserted-hpd.patch
queue-4.10/drm-i915-lspcon-enable-aux-interrupts-for-resume-time-initialization.patch
queue-4.10/drm-i915-gen9-enable-hotplug-detection-early.patch