On Fri, Mar 3, 2017 at 11:32 AM, Kenneth Graunke <kenn...@whitecape.org> wrote: > The OpenGL 4.5 specification's description of TexBuffer says: > > "The number of texels in the texture image is then clamped to an > implementation-dependent limit, the value of MAX_TEXTURE_BUFFER_SIZE." > > We set GL_MAX_TEXTURE_BUFFER_SIZE to 2^27. For buffers with a byte > element size, this is the maximum possible size we can encode in > SURFACE_STATE. If you bind a buffer object larger than this as a > texture buffer object, we'll exceed that limit and hit an isl assert: > > assert(num_elements <= (1ull << 27)); > > To fix this, clamp the size in bytes to MaxTextureSize / texel_size. > > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> > --- > src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > 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 8ffbc0a5fd5..e48b1e1d2d1 100644 > --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c > +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c > @@ -695,6 +695,24 @@ brw_update_buffer_texture_surface(struct gl_context *ctx, > bo = intel_bufferobj_buffer(brw, intel_obj, tObj->BufferOffset, size); > } > > + /* The ARB_texture_buffer_specification says: > + * > + * "The number of texels in the buffer texture's texel array is given > by > + * > + * floor(<buffer_size> / (<components> * sizeof(<base_type>)), > + * > + * where <buffer_size> is the size of the buffer object, in basic > + * machine units and <components> and <base_type> are the element > count > + * and base data type for elements, as specified in Table X.1. The > + * number of texels in the texel array is then clamped to the > + * implementation-dependent limit MAX_TEXTURE_BUFFER_SIZE_ARB." > + * > + * We need to clamp the size in bytes to MAX_TEXTURE_BUFFER_SIZE * stride, > + * so that when ISL divides by stride to obtain the number of texels, that > + * texel count is clamped to MAX_TEXTURE_BUFFER_SIZE. > + */ > + size = MIN2(size, ctx->Const.MaxTextureBufferSize * (unsigned) > texel_size); > + > if (brw_format == 0 && format != MESA_FORMAT_RGBA_FLOAT32) { > _mesa_problem(NULL, "bad format %s for texture buffer\n", > _mesa_get_format_name(format)); > -- > 2.11.1 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
LGTM. Reviewed-by: Anuj Phogat <anuj.pho...@gmail.com> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev