From ee59792c97176f12c1da31f29fc4c2aab187f06e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 28 Jan 2022 12:37:50 +0200 Subject: [PATCH] drm/i915: Disable DRRS on IVB/HSW port != A MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently we allow DRRS on IVB PCH ports, but we're missing a few programming steps meaning it is guaranteed to not work. And on HSW DRRS is not supported on anything but port A ever as only transcoder EDP has the M2/N2 registers (though I'm not sure if HSW ever has eDP on any other port). Starting from BDW all transcoders have the dynamically reprogrammable M/N registers so DRRS could work on any port. Stop initializing DRRS on ports where it cannot possibly work. Cc: stable@vger.kernel.org Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220128103757.22461-11-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula (cherry picked from commit f0d4ce59f4d48622044933054a0e0cefa91ba15e) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/display/intel_drrs.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_drrs.c b/drivers/gpu/drm/i915/display/intel_drrs.c index c1439fcb5a95..3ff149df4a77 100644 --- a/drivers/gpu/drm/i915/display/intel_drrs.c +++ b/drivers/gpu/drm/i915/display/intel_drrs.c @@ -405,6 +405,7 @@ intel_drrs_init(struct intel_connector *connector, struct drm_display_mode *fixed_mode) { struct drm_i915_private *dev_priv = to_i915(connector->base.dev); + struct intel_encoder *encoder = connector->encoder; struct drm_display_mode *downclock_mode = NULL; INIT_DELAYED_WORK(&dev_priv->drrs.work, intel_drrs_downclock_work); @@ -416,6 +417,13 @@ intel_drrs_init(struct intel_connector *connector, return NULL; } + if ((DISPLAY_VER(dev_priv) < 8 && !HAS_GMCH(dev_priv)) && + encoder->port != PORT_A) { + drm_dbg_kms(&dev_priv->drm, + "DRRS only supported on eDP port A\n"); + return NULL; + } + if (dev_priv->vbt.drrs_type != SEAMLESS_DRRS_SUPPORT) { drm_dbg_kms(&dev_priv->drm, "VBT doesn't support DRRS\n"); return NULL;