[Intel-gfx] [PATCH v4 17/17] drm/i915: Round TMDS clock to nearest

Ville Syrjala ville.syrjala at linux.intel.com
Wed Sep 7 09:10:57 UTC 2022


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Use round-to-nearest behavour when calculating the TMDS clock.
Matches what we do for most other clock related things.

Acked-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 3 ++-
 drivers/gpu/drm/i915/display/intel_hdmi.c    | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 1b7d26b9e985..407afd5888ed 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -4504,7 +4504,8 @@ int intel_crtc_dotclock(const struct intel_crtc_state *pipe_config)
 		dotclock = intel_dotclock_calculate(pipe_config->port_clock,
 						    &pipe_config->dp_m_n);
 	else if (pipe_config->has_hdmi_sink && pipe_config->pipe_bpp > 24)
-		dotclock = pipe_config->port_clock * 24 / pipe_config->pipe_bpp;
+		dotclock = DIV_ROUND_CLOSEST(pipe_config->port_clock * 24,
+					     pipe_config->pipe_bpp);
 	else
 		dotclock = pipe_config->port_clock;
 
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 09f85afeb2d4..7816b2a33fee 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1892,7 +1892,7 @@ int intel_hdmi_tmds_clock(int clock, int bpc, bool ycbcr420_output)
 	 *  1.5x for 12bpc
 	 *  1.25x for 10bpc
 	 */
-	return clock * bpc / 8;
+	return DIV_ROUND_CLOSEST(clock * bpc, 8);
 }
 
 static bool intel_hdmi_source_bpc_possible(struct drm_i915_private *i915, int bpc)
-- 
2.35.1



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