<div dir="ltr">On 2 February 2013 13:52, Kenneth Graunke <<a href="mailto:kenneth@whitecape.org" target="_blank">kenneth@whitecape.org</a>> wrote: <div class="gmail_extra"><div class="gmail_quote"> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Ivybridge doesn't appear to have the same errata as Sandybridge; no corruption was observed by setting it to more than the minimal correct value. It's possible that we were simply lucky, since the URB entries are 1024-bit on Ivybridge vs. 512-bit Sandybridge. Or perhaps the underlying hardware issue is fixed. Either way, we may as well program the minimum value since it's now readily available, likely to be more efficient, and possibly more correct. NOTE: This is a candidate for all stable branches. Signed-off-by: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> --- src/mesa/drivers/dri/i965/gen7_sf_state.c | 32 +++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/src/mesa/drivers/dri/i965/gen7_sf_state.c b/src/mesa/drivers/dri/i965/gen7_sf_state.c index b801b96..f7ad473 100644 --- a/src/mesa/drivers/dri/i965/gen7_sf_state.c +++ b/src/mesa/drivers/dri/i965/gen7_sf_state.c @@ -34,7 +34,6 @@ upload_sbe_state(struct brw_context *brw) { struct intel_context *intel = &brw->intel; struct gl_context *ctx = &intel->ctx; - uint32_t urb_entry_read_length; /* BRW_NEW_FRAGMENT_PROGRAM */ uint32_t num_outputs = _mesa_bitcount_64(brw->fragment_program->Base.InputsRead); /* _NEW_LIGHT */ @@ -48,22 +47,8 @@ upload_sbe_state(struct brw_context *brw) bool render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer); uint32_t point_sprite_origin; - /* CACHE_NEW_VS_PROG */ - urb_entry_read_length = ((brw->vs.prog_data->vue_map.num_slots + 1) / 2 - - urb_entry_read_offset); - if (urb_entry_read_length == 0) { - /* Setting the URB entry read length to 0 causes undefined behavior, so - * if we have no URB data to read, set it to 1. - */ - urb_entry_read_length = 1; - } - /* FINISHME: Attribute Swizzle Control Mode? */ - dw1 = - GEN7_SBE_SWIZZLE_ENABLE | - num_outputs << GEN7_SBE_NUM_OUTPUTS_SHIFT | - urb_entry_read_length << GEN7_SBE_URB_ENTRY_READ_LENGTH_SHIFT | - urb_entry_read_offset << GEN7_SBE_URB_ENTRY_READ_OFFSET_SHIFT; + dw1 = GEN7_SBE_SWIZZLE_ENABLE | num_outputs << GEN7_SBE_NUM_OUTPUTS_SHIFT; /* _NEW_POINT * @@ -123,6 +108,21 @@ upload_sbe_state(struct brw_context *brw) &max_source_attr); } + /* From the Ivy Bridge PRM, Volume 2, Part 1, documentation for + * 3DSTATE_SBE DWord 1 bits 15:11, "Vertex URB Entry Read Length": + * + * "This field should be set to the minimum length required to read the + * maximum source attribute. The maximum source attribute is indicated + * by the maximum value of the enabled Attribute # Source Attribute if + * Attribute Swizzle Enable is set, Number of Output Attributes-1 if + * enable is not set. + * + * read_length = ceiling((max_source_attr + 1) / 2)" + */ + uint32_t urb_entry_read_length = ALIGN(max_source_attr + 1, 2) / 2; + dw1 |= urb_entry_read_length << GEN6_SF_URB_ENTRY_READ_LENGTH_SHIFT | + urb_entry_read_offset << GEN6_SF_URB_ENTRY_READ_OFFSET_SHIFT; + </blockquote><div> </div><div>s/GEN6_SF/GEN7_SBE/ above. </div><div>(Fortunately these #defines are the same for GEN6 and GEN7 but it would be nice to use the right ones :)) </div><div>With that fixed, this series is: Reviewed-by: Paul Berry <<a href="mailto:stereotype441@gmail.com">stereotype441@gmail.com</a>> </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> for (; input_index < FRAG_ATTRIB_MAX; input_index++) attr_overrides[input_index] = 0; -- 1.8.1.2 _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div> </div></div>