From a5bcf8dde63142f36ae8ce720265d4c41a634d5c Mon Sep 17 00:00:00 2001 From: Imre Deak <imre.deak@intel.com> Date: Tue, 14 Jul 2020 18:31:41 +0300 Subject: [PATCH] drm/i915/ddi: Don't rewrite DDI_BUF_CTL reg during DP link training MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The value we program to DDI_BUF_CTL changes at the following places: - At enabling/disabling the output to configure the port width etc, and to enable/disable the DDI BUF function. - At the beginning/end of link re-training to disable/re-enable the DDI BUF function. - On HSW/BDW/SKL to change the voltage swing/pre-emph levels. Except of the above the value we program to the DDI_BUF_CTL register (intel_dp->DP) doesn't change, so no need to reprogram the register when changing the link training patterns (which is programmed via the DP_TP_CTL register on DDI platforms). v2: - Fix the commit message wrt. voltage/pre-emph level values in intel_dp->DP. (Ville) Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200714153141.10280-2-imre.deak@intel.com Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> --- drivers/gpu/drm/i915/display/intel_ddi.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index c467f18d5e1be..424d596715619 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -4060,7 +4060,6 @@ static void intel_ddi_set_link_train(struct intel_dp *intel_dp, { struct drm_i915_private *dev_priv = dp_to_i915(intel_dp); u8 train_pat_mask = drm_dp_training_pattern_mask(intel_dp->dpcd); - enum port port = dp_to_dig_port(intel_dp)->base.port; u32 temp; temp = intel_de_read(dev_priv, intel_dp->regs.dp_tp_ctl); @@ -4085,9 +4084,6 @@ static void intel_ddi_set_link_train(struct intel_dp *intel_dp, } intel_de_write(dev_priv, intel_dp->regs.dp_tp_ctl, temp); - - intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP); - intel_de_posting_read(dev_priv, DDI_BUF_CTL(port)); } static void intel_ddi_set_idle_link_train(struct intel_dp *intel_dp) -- GitLab