From: Ville Syrjälä Date: Thu, 10 Jul 2025 20:17:13 +0000 (+0300) Subject: drm/i915/dp: Don't switch to idle pattern before disable on pre-hsw X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f0da19347bccee1c20091e9fd597a2f197792021;p=users%2Fdwmw2%2Flinux.git drm/i915/dp: Don't switch to idle pattern before disable on pre-hsw For some reason we are switching over to the idle pattern before disabling the DP port on pre-hsw. AFAICS this has never been part of the documented sequence (and on hsw+ the spec explicitly says not to do this). Get rid of it. The code goes all the way back to commit 5eb08b69f510 ("drm/i915: enable DisplayPort support on IGDNG"), and it was accompanied by a 17ms delay which got changed to vbl wait in commit ab527efc2fea ("drm/i915: use wait_for_vblank instead of msleep(17)"), and was later completely removed in commit 93c9c19b3d25 ("drm/i915: remove unexplained vblank wait in the DP off code"). Smoke tested on g4x/snb/chv. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20250710201718.25310-3-ville.syrjala@linux.intel.com Reviewed-by: Imre Deak --- diff --git a/drivers/gpu/drm/i915/display/g4x_dp.c b/drivers/gpu/drm/i915/display/g4x_dp.c index 87f6b9602b16a..b54edf0d1c235 100644 --- a/drivers/gpu/drm/i915/display/g4x_dp.c +++ b/drivers/gpu/drm/i915/display/g4x_dp.c @@ -424,17 +424,6 @@ intel_dp_link_down(struct intel_encoder *encoder, drm_dbg_kms(display->drm, "\n"); - if ((display->platform.ivybridge && port == PORT_A) || - (HAS_PCH_CPT(display) && port != PORT_A)) { - intel_dp->DP &= ~DP_LINK_TRAIN_MASK_CPT; - intel_dp->DP |= DP_LINK_TRAIN_PAT_IDLE_CPT; - } else { - intel_dp->DP &= ~DP_LINK_TRAIN_MASK; - intel_dp->DP |= DP_LINK_TRAIN_PAT_IDLE; - } - intel_de_write(display, intel_dp->output_reg, intel_dp->DP); - intel_de_posting_read(display, intel_dp->output_reg); - intel_dp->DP &= ~DP_PORT_EN; intel_de_write(display, intel_dp->output_reg, intel_dp->DP); intel_de_posting_read(display, intel_dp->output_reg);