From 55314c5be4cbf933ab7fbd20f6aa49207e04c946 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Fri, 6 Nov 2015 18:12:27 -0800 Subject: [PATCH] i965/skl/gt4: Fix URB programming restriction. The comment in the code details the restriction. Thanks to Ken for having a very helpful conversation with me, and spotting the blurb in the link I sent him :P. There are still stability problems for me on GT4, but this definitely helps with some of the failures. v2: Comment fixes Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Jordan Justen Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_device_info.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_device_info.c b/src/mesa/drivers/dri/i965/brw_device_info.c index 2ebc0845300..45505507be7 100644 --- a/src/mesa/drivers/dri/i965/brw_device_info.c +++ b/src/mesa/drivers/dri/i965/brw_device_info.c @@ -337,6 +337,15 @@ static const struct brw_device_info brw_device_info_skl_gt3 = { static const struct brw_device_info brw_device_info_skl_gt4 = { GEN9_FEATURES, .gt = 4, + /* From the "L3 Allocation and Programming" documentation: + * + * "URB is limited to 1008KB due to programming restrictions. This is not a + * restriction of the L3 implementation, but of the FF and other clients. + * Therefore, in a GT4 implementation it is possible for the programmed + * allocation of the L3 data array to provide 3*384KB=1152KB for URB, but + * only 1008KB of this will be used." + */ + .urb.size = 1008 / 3, }; static const struct brw_device_info brw_device_info_bxt = { -- 2.30.2