There is a bug report https://bugs.freedesktop.org/show_bug.cgi?id=91393 indicating that there are panels that do not support link training starting with non-zero voltage swing and pre-emphasis values. This patch proposes to make this fast link training feature as one module parameter. To take more conservative approach this feature is disabled by default. Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_params.c | 4 ++++ drivers/gpu/drm/i915/intel_dp_link_training.c | 11 ++++++++++- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index a47e0f4..dc2d5a0 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2669,6 +2669,7 @@ struct i915_params { bool verbose_state_checks; bool nuclear_pageflip; int edp_vswing; + bool enable_dp_flt; }; extern struct i915_params i915 __read_mostly; diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 835d609..aea5d47 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -56,6 +56,7 @@ struct i915_params i915 __read_mostly = { .edp_vswing = 0, .enable_guc_submission = false, .guc_log_level = -1, + .enable_dp_flt = false, }; module_param_named(modeset, i915.modeset, int, 0400); @@ -202,3 +203,6 @@ MODULE_PARM_DESC(enable_guc_submission, "Enable GuC submission (default:false)") module_param_named(guc_log_level, i915.guc_log_level, int, 0400); MODULE_PARM_DESC(guc_log_level, "GuC firmware logging level (-1:disabled (default), 0-3:enabled)"); + +module_param_named_unsafe(enable_dp_flt, i915.enable_dp_flt, bool, 0400); +MODULE_PARM_DESC(enable_dp_flt, "Enable DP fast link training (default:false)"); diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 8888793..f8b6d69 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -85,8 +85,17 @@ static bool intel_dp_reset_link_train(struct intel_dp *intel_dp, uint8_t dp_train_pat) { - if (!intel_dp->train_set_valid) + if (i915.enable_dp_flt) { + DRM_DEBUG_KMS("DP flt enabled, train set valid: %s\n", + intel_dp->train_set_valid ? "true" : "false"); + + if (!intel_dp->train_set_valid) + memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); + } else { + DRM_DEBUG_KMS("DP flt disabled\n"); memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); + } + intel_dp_set_signal_levels(intel_dp); return intel_dp_set_link_train(intel_dp, dp_train_pat); } -- 1.9.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
