From: Ville Syrjälä Date: Thu, 27 Feb 2014 12:23:14 +0000 (+0200) Subject: drm/i915: Use DIV_ROUND_UP() when calculating number of required FDI lanes X-Git-Tag: firefly_0821_release~176^2~3773^2~63^2~270 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=619d4d04723346bf6ca3273668e0ba2582e8de36;p=firefly-linux-kernel-4.4.55.git drm/i915: Use DIV_ROUND_UP() when calculating number of required FDI lanes If we need precisely N lanes to satisfy the FDI bandwidth requirement, the code would still claim that we need N+1 lanes. Use DIV_ROUND_UP() to get a more accurate answer. Signed-off-by: Ville Syrjälä Reviewed-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 45bd176b68b5..227f6602de0a 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6161,7 +6161,7 @@ int ironlake_get_lanes_required(int target_clock, int link_bw, int bpp) * is 2.5%; use 5% for safety's sake. */ u32 bps = target_clock * bpp * 21 / 20; - return bps / (link_bw * 8) + 1; + return DIV_ROUND_UP(bps, link_bw * 8); } static bool ironlake_needs_fb_cb_tune(struct dpll *dpll, int factor)