The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4b84b4a5507913ee0da27b1f1b27671937839de6 Mon Sep 17 00:00:00 2001 From: Imre Deak <imre.deak@xxxxxxxxx> Date: Fri, 27 Jan 2017 11:39:19 +0200 Subject: [PATCH] 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 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@xxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+ Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> Reviewed-by: Shashank Sharma <shashank.sharma@xxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/1485509961-9010-3-git-send-email-imre.deak@xxxxxxxxx (cherry picked from commit 390b4e00241ce14ca3967c4698c8f6a158c5a674) Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 3d8ac8aa7214..52822d694746 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4406,8 +4406,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, * * 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); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 0cec0013ace0..a60f442f2686 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1485,6 +1485,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, bool intel_dp_read_desc(struct intel_dp *intel_dp); int intel_dp_link_required(int pixel_clock, int bpp); int intel_dp_max_data_rate(int max_link_clock, int max_lanes); +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); diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c index f6d4e6940257..c300647ef604 100644 --- a/drivers/gpu/drm/i915/intel_lspcon.c +++ b/drivers/gpu/drm/i915/intel_lspcon.c @@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) 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) @@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) 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;