diff options
| author |   Lee, Shawn C <shawn.c.lee@intel.com> | 2018-09-11 23:22:50 -0700 |
|---|---|---|
| committer |   Jani Nikula <jani.nikula@intel.com> | 2018-09-19 16:44:12 +0300 |
| commit | 53ca2edcf033f3368b2dc0ef3cbcc2f47d556d13 (patch) | |
| tree | c7a8b6e2c93bb03c8cd5b4d3eb5b68e2154a3fe0 /drivers/gpu/drm/i915/intel_dp_mst.c | |
| parent | drm: Add support for device_id based detection. (diff) | |
| download | linux-dev-53ca2edcf033f3368b2dc0ef3cbcc2f47d556d13.tar.xz linux-dev-53ca2edcf033f3368b2dc0ef3cbcc2f47d556d13.zip | |
drm: Change limited M/N quirk to constant N quirk.
Some DP dongles in particular seem to be fussy about too large
link M/N values. Set specific value for N divider can resolve
this issue per dongle vendor's comment. So configure N as
constant value (0x8000) to instead of reduce M/N formula when
specific DP dongle connected.
v2: add more comments for issue description and fix typo.
v3: add lost commit messages back for version 2
v4: send patch to both intel-gfx and dri-devel
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Tested-by: Clint Taylor <clinton.a.taylor@intel.com>
Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536733371-25004-3-git-send-email-shawn.c.lee@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp_mst.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp_mst.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c index 7e3e01607643..b7505879b1f7 100644 --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -45,8 +45,8 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, int lane_count, slots; const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode; int mst_pbn; - bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc, - DP_DPCD_QUIRK_LIMITED_M_N); + bool constant_n = drm_dp_has_quirk(&intel_dp->desc, + DP_DPCD_QUIRK_CONSTANT_N); if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN) return false; @@ -87,7 +87,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, adjusted_mode->crtc_clock, pipe_config->port_clock, &pipe_config->dp_m_n, - reduce_m_n); + constant_n); pipe_config->dp_m_n.tu = slots; |