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| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-07-18 17:43:39 +0300 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-10-18 17:04:34 +0300 |
| commit | 98c93394ba907e6b741c67dc6affea78c2a940a0 (patch) | |
| tree | c94c0de07e58c0afe308be809c84f1d7fe111583 | |
| parent | c08f995a284dc202a934530ee73cc7136665af38 (diff) | |
| download | linux-98c93394ba907e6b741c67dc6affea78c2a940a0.tar.xz | |
drm/i915: Refuse modes with hdisplay==4096 on pre-HSW DP
The DP port/pipe goes wonky if we try to use timings with
hdisplay==4096 on pre-HSW platforms. The link fails to train
and the pipe may not signal vblank interrupts. On HDMI such at
mode works just fine (tested on ELK/SNB/CHV). So let's refuse
such modes on DP on older platforms.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190718144340.1114-1-ville.syrjala@linux.intel.com
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index c4c081c79dd9..3792d143bea9 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -591,6 +591,25 @@ static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp, return 0; } +static bool intel_dp_hdisplay_bad(struct drm_i915_private *dev_priv, + int hdisplay) +{ + /* + * Older platforms don't like hdisplay==4096 with DP. + * + * On ILK/SNB/IVB the pipe seems to be somewhat running (scanline + * and frame counter increment), but we don't get vblank interrupts, + * and the pipe underruns immediately. The link also doesn't seem + * to get trained properly. + * + * On CHV the vblank interrupts don't seem to disappear but + * otherwise the symptoms are similar. + * + * TODO: confirm the behaviour on HSW+ + */ + return hdisplay == 4096 && !HAS_DDI(dev_priv); +} + static enum drm_mode_status intel_dp_mode_valid(struct drm_connector *connector, struct drm_display_mode *mode) @@ -626,6 +645,9 @@ intel_dp_mode_valid(struct drm_connector *connector, max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); mode_rate = intel_dp_link_required(target_clock, 18); + if (intel_dp_hdisplay_bad(dev_priv, mode->hdisplay)) + return MODE_H_ILLEGAL; + /* * Output bpp is stored in 6.4 format so right shift by 4 to get the * integer value since we support only integer values of bpp. @@ -2345,6 +2367,9 @@ intel_dp_compute_config(struct intel_encoder *encoder, if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) return -EINVAL; + if (intel_dp_hdisplay_bad(dev_priv, adjusted_mode->crtc_hdisplay)) + return -EINVAL; + ret = intel_dp_compute_link_config(encoder, pipe_config, conn_state); if (ret < 0) return ret; |