From: Eric Anholt Date: Tue, 22 Feb 2011 07:46:52 +0000 (-0800) Subject: i965: Apply a workaround for the Ironlake "vertex flashing". X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1a57717bbe8a2cedf2e1bb72cfd7ec85cd2350fc;p=mesa.git i965: Apply a workaround for the Ironlake "vertex flashing". This is an awful hack and will hurt performance on Ironlake, but we're at a loss as to what's going wrong otherwise. This is the only common variable we've found that avoids the problem on 4 applications (CelShading, gnome-shell, Pill Popper, and my GLSL demo), while other variables we've tried appear to only be confounding. Neither the specifications nor the hardware team have been able to provide any enlightenment, despite much searching. https://bugs.freedesktop.org/show_bug.cgi?id=29172 Tested by: Chris Lord (Pill Popper) Tested by: Ryan Lortie (gnome-shell) --- diff --git a/src/mesa/drivers/dri/i965/brw_vs_state.c b/src/mesa/drivers/dri/i965/brw_vs_state.c index be923138617..c3a7cc247c5 100644 --- a/src/mesa/drivers/dri/i965/brw_vs_state.c +++ b/src/mesa/drivers/dri/i965/brw_vs_state.c @@ -96,7 +96,14 @@ vs_unit_create_from_key(struct brw_context *brw, struct brw_vs_unit_key *key) * and those dwords will be written to the second URB handle when we * brw_urb_WRITE() results. */ - vs.thread1.single_program_flow = 0; + /* Disable single program flow on Ironlake. We cannot reliably get + * all applications working without it. See: + * https://bugs.freedesktop.org/show_bug.cgi?id=29172 + * + * The most notable and reliably failing application is the Humus + * demo "CelShading" + */ + vs.thread1.single_program_flow = (intel->gen == 5); if (intel->gen == 5) vs.thread1.binding_table_entry_count = 0; /* hardware requirement */