[PATCH] drm/i915/display: Add upper limit check for pixel clock

[Chaitanya Kumar Borah]

Add upper limit check for pixel clock by platform. Limits don't apply
when DSC is enabled.

BSpec: 49199, 68912

Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 12 ++++++++++++
 drivers/gpu/drm/i915/display/intel_display.h |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c      |  3 +++
 3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index cd6fa1669074..469a6adc22d7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7867,6 +7867,18 @@ void intel_setup_outputs(struct intel_display *display)
 	drm_helper_move_panel_connectors_to_head(display->drm);
 }
 
+int intel_dotclock_limit(struct intel_display *display)
+{
+	if (DISPLAY_VERx100(display) == 3002)
+		return 937500;
+	else if (DISPLAY_VER(display) >= 30)
+		return 1350000;
+	else if (DISPLAY_VER(display) >= 13)
+		return 1200000;
+	else
+		return 1100000;
+}
+
 static int max_dotclock(struct intel_display *display)
 {
 	int max_dotclock = display->cdclk.max_dotclk_freq;
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 37e2ab301a80..9ad896a15ba7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -486,6 +486,7 @@ void intel_cpu_transcoder_get_m2_n2(struct intel_crtc *crtc,
 				    struct intel_link_m_n *m_n);
 int intel_dotclock_calculate(int link_freq, const struct intel_link_m_n *m_n);
 int intel_crtc_dotclock(const struct intel_crtc_state *pipe_config);
+int intel_dotclock_limit(struct intel_display *display);
 enum intel_display_power_domain intel_port_to_power_domain(struct intel_digital_port *dig_port);
 enum intel_display_power_domain
 intel_aux_power_domain(struct intel_digital_port *dig_port);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index f48912f308df..3ff2beeed801 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1507,6 +1507,9 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 		dsc = dsc_max_compressed_bpp && dsc_slice_count;
 	}
 
+	if (target_clock > (intel_dotclock_limit(display) * num_joined_pipes) && !dsc)
+		return MODE_CLOCK_HIGH;
+
 	if (intel_dp_joiner_needs_dsc(display, num_joined_pipes) && !dsc)
 		return MODE_CLOCK_HIGH;
 
-- 
2.25.1