diff options
| author | Kai-Heng Feng <kai.heng.feng@canonical.com> | 2021-08-20 15:52:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 12:39:17 +0200 |
| commit | dc1fd142dcf212b849977ba538b35479f02f416f (patch) | |
| tree | 856466f3daa5e6ea2194478443056b5532f02eb3 /drivers/gpu | |
| parent | d717dcf122eae5c5d9e4fa4e8ff52b727f3a8173 (diff) | |
drm/i915/dp: Use max params for panels < eDP 1.4
commit c8dead5751b81dfa6b10449b740ed1062ff670c5 upstream.
Users reported that after commit 2bbd6dba84d4 ("drm/i915: Try to use
fast+narrow link on eDP again and fall back to the old max strategy on
failure"), the screen starts to have wobbly effect.
Commit a5c936add6a2 ("drm/i915/dp: Use slow and wide link training for
everything") doesn't help either, that means the affected eDP 1.2 panels
only work with max params.
So use max params for panels < eDP 1.4 as Windows does to solve the
issue.
v3:
- Do the eDP rev check in intel_edp_init_dpcd()
v2:
- Check eDP 1.4 instead of DPCD 1.1 to apply max params
Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3714
Fixes: 2bbd6dba84d4 ("drm/i915: Try to use fast+narrow link on eDP again and fall back to the old max strategy on failure")
Fixes: a5c936add6a2 ("drm/i915/dp: Use slow and wide link training for everything")
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210820075301.693099-1-kai.heng.feng@canonical.com
(cherry picked from commit d7f213c131adf0bec8b731553eb82990cdac265d)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 862c1df69cc2..d511e578ba79 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2453,11 +2453,14 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) */ if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) == - sizeof(intel_dp->edp_dpcd)) + sizeof(intel_dp->edp_dpcd)) { drm_dbg_kms(&dev_priv->drm, "eDP DPCD: %*ph\n", (int)sizeof(intel_dp->edp_dpcd), intel_dp->edp_dpcd); + intel_dp->use_max_params = intel_dp->edp_dpcd[0] < DP_EDP_14; + } + /* * This has to be called after intel_dp->edp_dpcd is filled, PSR checks * for SET_POWER_CAPABLE bit in intel_dp->edp_dpcd[1] |