From 7039a6dc17a9ae73dcf38fe16e9e78dedbfb26e0 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 7 Dec 2016 19:28:09 +0200 Subject: [PATCH] drm/i915: Simplify SWIDTHSW calculation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The formula in Bspec for computing the overlay SWIDTHSW is overly obfuscated. Simplify the formula to something that's easily parsed by humans. Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/1481131693-27993-8-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/intel_overlay.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c index 935e6bc2ccad..9be9522f1dd1 100644 --- a/drivers/gpu/drm/i915/intel_overlay.c +++ b/drivers/gpu/drm/i915/intel_overlay.c @@ -567,19 +567,17 @@ static int uv_vsubsampling(u32 format) static u32 calc_swidthsw(struct drm_i915_private *dev_priv, u32 offset, u32 width) { - u32 mask, shift, ret; - if (IS_GEN2(dev_priv)) { - mask = 0x1f; - shift = 5; - } else { - mask = 0x3f; - shift = 6; - } - ret = ((offset + width + mask) >> shift) - (offset >> shift); - if (!IS_GEN2(dev_priv)) - ret <<= 1; - ret -= 1; - return ret << 2; + u32 sw; + + if (IS_GEN2(dev_priv)) + sw = ALIGN((offset & 31) + width, 32); + else + sw = ALIGN((offset & 63) + width, 64); + + if (sw == 0) + return 0; + + return (sw - 32) >> 3; } static const u16 y_static_hcoeffs[N_HORIZ_Y_TAPS * N_PHASES] = { -- 2.20.1