From: Paulo Zanoni Date: Fri, 3 May 2013 20:23:40 +0000 (-0300) Subject: drm/i915: fix haswell linetime watermarks calculation X-Git-Tag: firefly_0821_release~176^2~5752^2~105^2~65 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=eaa591ec528ad75bb4c77606c5cb671f05e04db6;p=firefly-linux-kernel-4.4.55.git drm/i915: fix haswell linetime watermarks calculation Move the "*8" calculation to the left side so we don't propagate rounding errors. Also use DIV_ROUND_CLOSEST because that's what the spec says we need to do. Signed-off-by: Paulo Zanoni Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 198d9c9ada68..2c406ddc6354 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2093,7 +2093,7 @@ haswell_update_linetime_wm(struct drm_device *dev, struct drm_crtc *crtc) * row at the given clock rate, multiplied by 8. * */ temp |= PIPE_WM_LINETIME_TIME( - ((mode->htotal * 1000) / mode->clock) * 8); + DIV_ROUND_CLOSEST(mode->htotal * 1000 * 8, mode->clock)); /* IPS watermarks are only used by pipe A, and are ignored by * pipes B and C. They are calculated similarly to the common