From fcd5af4a916b4ba7860ba27eb47404934bde0d08 Mon Sep 17 00:00:00 2001 From: Paul Berry Date: Mon, 9 Jan 2012 15:36:27 -0800 Subject: [PATCH] i965: Set pitch of pull constant buffers to 16. We always access pull constant buffers using the message types "OWord Block Read" or "OWord Dual Block Read". According to the Sandy Bridge PRM, Vol 4 Part 1, pages 214 and 218, when using these messages: "the surface pitch is ignored, the surface is treated as a 1-dimensional surface. An element size (pitch) of 16 bytes is used to determine the size of the buffer for out-of-bounds checking if using the surface state model." Previously we were setting the pitch for pull constant buffers to the size of the whole constant buffer--this made no sense and would have led to incorrect behavior if it were not for the fact that the pitch is ignored. For clarity, this patch sets the pitch for pull constant buffers to 16 bytes, consistent with the hardware's behavior. v2: Clarify the meaning of the ignored values by writing them as (16 - 1). Reviewed-by: Eric Anholt Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 2 +- src/mesa/drivers/dri/i965/gen7_wm_surface_state.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c index b40f5e1b87a..159509be82f 100644 --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c @@ -702,7 +702,7 @@ brw_create_constant_surface(struct brw_context *brw, ((w >> 7) & 0x1fff) << BRW_SURFACE_HEIGHT_SHIFT); surf[3] = (((w >> 20) & 0x7f) << BRW_SURFACE_DEPTH_SHIFT | - (width * 16 - 1) << BRW_SURFACE_PITCH_SHIFT); + (16 - 1) << BRW_SURFACE_PITCH_SHIFT); /* ignored */ surf[4] = 0; surf[5] = 0; diff --git a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c index 1c0183b70c1..aed0b5d73fc 100644 --- a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c +++ b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c @@ -157,7 +157,7 @@ gen7_create_constant_surface(struct brw_context *brw, surf->ss2.width = w & 0x7f; /* bits 6:0 of size or width */ surf->ss2.height = (w >> 7) & 0x1fff; /* bits 19:7 of size or width */ surf->ss3.depth = (w >> 20) & 0x7f; /* bits 26:20 of size or width */ - surf->ss3.pitch = (width * 16) - 1; /* ignored?? */ + surf->ss3.pitch = (16 - 1); /* ignored */ gen7_set_surface_tiling(surf, I915_TILING_NONE); /* tiling now allowed */ /* Emit relocation to surface contents. Section 5.1.1 of the gen4 -- 2.11.0