i965/gen4: Subtract 1 from buffer sizes

The PRM states that the values put in Width, Height, and Depth should be
various bits from the value size - 1.  We seem to have done this wrong
more-or-less from the start.

Reviewed-by: Chad Versace <chad.versace@intel.com>
Cc: "11.1 11.2 12.0" <mesa-stable@lists.freedesktop.org>

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 7b2953c0323c1d27d19355ef4096aa1b844c1ce0..cfce2c9cd09f8101013cc71ee66d8be026266197 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -237,9 +237,9 @@ gen4_emit_buffer_surface_state(struct brw_context *brw,
              surface_format << BRW_SURFACE_FORMAT_SHIFT |
              (brw->gen >= 6 ? BRW_SURFACE_RC_READ_WRITE : 0);
    surf[1] = (bo ? bo->offset64 : 0) + buffer_offset; /* reloc */
-   surf[2] = (buffer_size & 0x7f) << BRW_SURFACE_WIDTH_SHIFT |
-             ((buffer_size >> 7) & 0x1fff) << BRW_SURFACE_HEIGHT_SHIFT;
-   surf[3] = ((buffer_size >> 20) & 0x7f) << BRW_SURFACE_DEPTH_SHIFT |
+   surf[2] = ((buffer_size - 1) & 0x7f) << BRW_SURFACE_WIDTH_SHIFT |
+             (((buffer_size - 1) >> 7) & 0x1fff) << BRW_SURFACE_HEIGHT_SHIFT;
+   surf[3] = (((buffer_size - 1) >> 20) & 0x7f) << BRW_SURFACE_DEPTH_SHIFT |
              (pitch - 1) << BRW_SURFACE_PITCH_SHIFT;
 
    /* Emit relocation to surface contents.  The 965 PRM, Volume 4, section