From: Ville Syrjälä ville.syrjala@linux.intel.com
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 anusha.srivatsa@intel.com Cc: Manasi Navare manasi.d.navare@intel.com Fixes: 240999cf339f ("i915/dp/fec: Add fec_enable to the crtc state.") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20190326144903.6617-1-ville.sy... Reviewed-by: Manasi Navare manasi.d.navare@intel.com (cherry picked from commit 6fd3134ae3551d4802a04669c0f39f2f5c56f77d) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/intel_dp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- 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( 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_enc 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;