<div class="gmail_quote">On 9 July 2012 13:36, Chad Versace <<a href="mailto:chad.versace@linux.intel.com" target="_blank">chad.versace@linux.intel.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"><div class="h5">On 07/06/2012 03:29 PM, Paul Berry wrote: > To implement Gen7's CMS MSAA layout, we need an extra buffer, the MCS > (Multisample Control Surface) buffer. This patch introduces code for > allocating and deallocating the buffer, and storing a pointer to it in > the intel_mipmap_tree struct. > > No functional change, since the CMS layout is not enabled yet. > --- > src/mesa/drivers/dri/intel/intel_fbo.c | 9 +++++ > src/mesa/drivers/dri/intel/intel_mipmap_tree.c | 45 ++++++++++++++++++++++++ > src/mesa/drivers/dri/intel/intel_mipmap_tree.h | 14 +++++++ > 3 files changed, 68 insertions(+), 0 deletions(-) > > diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c > index a801bb7..6530b99 100644 > --- a/src/mesa/drivers/dri/intel/intel_fbo.c > +++ b/src/mesa/drivers/dri/intel/intel_fbo.c > @@ -282,6 +282,15 @@ intel_alloc_renderbuffer_storage(struct gl_context * ctx, struct gl_renderbuffer > } > } > > + if (irb->mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS) { > + bool ok = intel_miptree_alloc_mcs(intel, irb->mt, rb->NumSamples); > + if (!ok) { > + intel_miptree_release(&irb->mt->hiz_mt); > + intel_miptree_release(&irb->mt); > + return false; > + } > + } > + > return true; > } </div></div>FYI, though it causes no harm, there's no need to release the hiz miptree separately from its parent. The miptree's destructor takes care of that. </blockquote><div> Good point. I'll remove it. </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <div class="im"> > + /* From the Ivy Bridge PRM, Vol 2 Part 1 p326: > + * > + * When MCS buffer is enabled and bound to MSRT, it is required that it > + * is cleared prior to any rendering. > + * > + * Since we don't use the MCS buffer for any purpose other than rendering, > + * it makes sense to just clear it immediately upon allocation. > + */ > + void *data = intel_region_map(intel, mt->mcs_mt->region, 0); > + memset(data, 0, mt->mcs_mt->region->bo->size); > + intel_region_unmap(intel, mt->mcs_mt->region); </div>But the clear value for a 4x MCS is 0xff. Am I missing something? </blockquote><div> Yes, you're right. I had a convoluted reason for believing that initializing to 0 was better, but it's not standing up to scrutiny. I'll change it to 0xff. </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> -Chad </blockquote></div>