From: Ville Syrjälä Date: Fri, 27 Jun 2014 21:40:34 +0000 (+0300) Subject: drm/i915: Fix threshold for choosing 32 vs. 64 precisions for VLV DDL values X-Git-Tag: v3.17-rc1~81^2~8 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=69bbeb4ae7b05c094b593b5df4f7a68f713589be;p=karo-tx-linux.git drm/i915: Fix threshold for choosing 32 vs. 64 precisions for VLV DDL values The DDL registers can hold 7bit numbers. Make the most of those seven bits by adjusting the threshold where we switch between the 64 vs. 32 precision multipliers. Also we compute 'entries' to make the decision about precision, and then we recompute the same value to calculate the actual drain latency. Just use the already calculate 'entries' there. Reviewed-by: Paulo Zanoni Signed-off-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 91edd47e9bce..615e341682c3 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -1287,15 +1287,14 @@ static bool vlv_compute_drain_latency(struct drm_device *dev, pixel_size = crtc->primary->fb->bits_per_pixel / 8; /* BPP */ entries = (clock / 1000) * pixel_size; - *plane_prec_mult = (entries > 256) ? + *plane_prec_mult = (entries > 128) ? DRAIN_LATENCY_PRECISION_64 : DRAIN_LATENCY_PRECISION_32; - *plane_dl = (64 * (*plane_prec_mult) * 4) / ((clock / 1000) * - pixel_size); + *plane_dl = (64 * (*plane_prec_mult) * 4) / entries; entries = (clock / 1000) * 4; /* BPP is always 4 for cursor */ - *cursor_prec_mult = (entries > 256) ? + *cursor_prec_mult = (entries > 128) ? DRAIN_LATENCY_PRECISION_64 : DRAIN_LATENCY_PRECISION_32; - *cursor_dl = (64 * (*cursor_prec_mult) * 4) / ((clock / 1000) * 4); + *cursor_dl = (64 * (*cursor_prec_mult) * 4) / entries; return true; }