[RFC] drm/i915/display: Update vtotal math to address 32b build

[Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>]

Fix few divisions which may not work on 32b builds.

Use DIV_ROUND_UP, with that expecting deviate params
from +/- 1 accuracy in value.

Fixes: 1676ecd303ac ("drm/i915: Compute CMRR and calculate vtotal")
Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
---
 drivers/gpu/drm/i915/display/intel_vrr.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index 05f67dc9d98d..5112961f6964 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -122,10 +122,11 @@ is_cmrr_frac_required(struct intel_crtc_state *crtc_state)
 
 	actual_refresh_k =
 		drm_mode_vrefresh(adjusted_mode) * FIXED_POINT_PRECISION;
-	pixel_clock_per_line =
-		adjusted_mode->crtc_clock * 1000 / adjusted_mode->crtc_htotal;
+	pixel_clock_per_line = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
+					    adjusted_mode->crtc_htotal);
 	calculated_refresh_k =
-		pixel_clock_per_line * FIXED_POINT_PRECISION / adjusted_mode->crtc_vtotal;
+		DIV_ROUND_UP(pixel_clock_per_line * FIXED_POINT_PRECISION,
+			     adjusted_mode->crtc_vtotal);
 
 	if ((actual_refresh_k - calculated_refresh_k) < CMRR_PRECISION_TOLERANCE)
 		return false;
@@ -149,7 +150,8 @@ cmrr_get_vtotal(struct intel_crtc_state *crtc_state, bool video_mode_required)
 
 	crtc_state->cmrr.cmrr_n =
 		desired_refresh_rate * adjusted_mode->crtc_htotal * multiplier_n;
-	vtotal = (adjusted_mode->crtc_clock * 1000 * multiplier_n) / crtc_state->cmrr.cmrr_n;
+	vtotal = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000 * multiplier_n,
+			      crtc_state->cmrr.cmrr_n);
 	adjusted_pixel_rate = adjusted_mode->crtc_clock * 1000 * multiplier_m;
 	crtc_state->cmrr.cmrr_m = do_div(adjusted_pixel_rate, crtc_state->cmrr.cmrr_n);
 
-- 
2.45.2