[PATCH 1/2] drm/i915: Fix bug while calculating the clock value using do_div in ironlake_crtc_clock_get

[Furquan Shaikh]

We need to round up the values since the comparison in drm_mode_equal might fail if division
results in fractional part

Signed-off-by: Furquan Shaikh <furquan at google.com>
---
 drivers/gpu/drm/i915/intel_display.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0f40f8e..e0069f4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7190,7 +7190,11 @@ static void ironlake_crtc_clock_get(struct intel_crtc *crtc,
 		return;
 
 	clock = ((u64)link_m * (u64)link_freq * (u64)repeat);
-	do_div(clock, link_n);
+	/* This is required because the value comes out to be in fraction
+	   (eg. 70699.54). Need to round it up since values are compared in
+	   drm_mode_equal
+	*/
+	clock = DIV_ROUND_UP_ULL(clock, link_n);
 
 	pipe_config->adjusted_mode.clock = clock;
 }
-- 
1.8.3