[PATCH 8/9] drm/i915/display: Implement Wa_14021768792 for BMG DP for link_m/n ratio > 10

[Ankit Nautiyal]

Handle the bypass logic for the M/N ratio limit for DP.
Calculate the M/N ratio, check if it can bypass the limit, and set the
appropriate flags for the workaround.

Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |  1 -
 drivers/gpu/drm/i915/display/intel_display.h |  2 ++
 drivers/gpu/drm/i915/display/intel_dp.c      | 11 ++++++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c 
b/drivers/gpu/drm/i915/display/intel_display.c
index bb50928762f6..ee15289221d7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -3406,7 +3406,6 @@ void bmg_bypass_m_n_limit_read(struct intel_crtc *crtc,
                m_n->bypass_m_n_ratio_limit = true;
 }
 
-static
 bool intel_display_can_bypass_m_n_limit(struct intel_display *display,
                                        int m_n_ratio,
                                        enum pipe pipe)
diff --git a/drivers/gpu/drm/i915/display/intel_display.h 
b/drivers/gpu/drm/i915/display/intel_display.h
index bfa3db219b9c..a7134dd15687 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -562,5 +562,7 @@ int intel_crtc_num_joined_pipes(const struct 
intel_crtc_state *crtc_state);
 void intel_display_get_link_m_n(u32 *link_m, u32 *link_n,
                                u32 pixel_clock,
                                u32 link_clock);
+bool intel_display_can_bypass_m_n_limit(struct intel_display *display,
+                                       int m_n_ratio, enum pipe pipe);
 
 #endif
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c 
b/drivers/gpu/drm/i915/display/intel_dp.c
index a1114d1059dd..a5ab7d694dbe 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3012,10 +3012,19 @@ void intel_dp_check_m_n_ratio(struct intel_crtc_state 
*crtc_state,
 
        m_n_ratio = DIV_ROUND_UP(m_n->link_m, m_n->link_n);
 
-       if (m_n_ratio > intel_dp_get_max_m_n_ratio())
+       if (m_n_ratio > intel_dp_get_max_m_n_ratio()) {
+               struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+               enum pipe pipe = crtc->pipe;
+
+               if (intel_display_can_bypass_m_n_limit(display, m_n_ratio, 
pipe)) {
+                       m_n->bypass_m_n_ratio_limit = true;
+                       drm_dbg_kms(display->drm, "Bypassing Link_m/Link_n 
ratio limit\n");
+                       return;
+               }
                drm_WARN(display->drm, 1,
                         "Link M/N ratio (%d) exceeds max allowed (%d)\n",
                         m_n_ratio, intel_dp_get_max_m_n_ratio());
+       }
 }
 
 static void
-- 
2.45.2