From 2c393b93877a6f88b87d59694557b5467b8e3977 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 26 Mar 2019 16:49:02 +0200 Subject: [PATCH] drm/i915: Do not enable FEC without DSC MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit BugLink: https://bugs.launchpad.net/bugs/1830934 commit 5aae7832d1b4ec614996ea0f4fafc4d9855ec0b0 upstream. Currently we enable FEC even when DSC is no used. While that is theoretically valid supposedly there isn't much of a benefit from this. But more importantly we do not account for the FEC link bandwidth overhead (2.4%) in the non-DSC link bandwidth computations. So the code may think we have enough bandwidth when we in fact do not. Cc: stable@vger.kernel.org Cc: Anusha Srivatsa Cc: Manasi Navare Fixes: 240999cf339f ("i915/dp/fec: Add fec_enable to the crtc state.") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20190326144903.6617-1-ville.syrjala@linux.intel.com Reviewed-by: Manasi Navare (cherry picked from commit 6fd3134ae3551d4802a04669c0f39f2f5c56f77d) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Bader Signed-off-by: Kleber Sacilotto de Souza --- drivers/gpu/drm/i915/intel_dp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index dcd1df5322e8..21c6016ccba5 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1871,6 +1871,9 @@ static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp, u8 dsc_max_bpc; int pipe_bpp; + pipe_config->fec_enable = !intel_dp_is_edp(intel_dp) && + intel_dp_supports_fec(intel_dp, pipe_config); + if (!intel_dp_supports_dsc(intel_dp, pipe_config)) return false; @@ -2097,9 +2100,6 @@ intel_dp_compute_config(struct intel_encoder *encoder, if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) return false; - pipe_config->fec_enable = !intel_dp_is_edp(intel_dp) && - intel_dp_supports_fec(intel_dp, pipe_config); - if (!intel_dp_compute_link_config(encoder, pipe_config, conn_state)) return false; -- 2.39.5