[Mesa-dev] [PATCH] radv: Unset ZRANGE_PRECISION when depth was zeroed

[James Legg]

On Thu, 2018-03-22 at 02:36 +0100, Bas Nieuwenhuizen wrote:
> On Thu, Mar 8, 2018 at 12:59 PM, James Legg <jlegg at feralinteractive.com> wrote:
> > This avoids bug 105396 somehow. I suspect it is a VI and GFX9 hardware
> > bug which PAL calls WaTcCompatZRange, but I don't know for sure.
> > 
> > In the VK_FORMAT_D32_SFLOAT case, TILE_STENCIL_DISABLE is not set for
> > tc compatible image formats regardless of not having a stencil aspect.
> > If TILE_STENCIL_DISABLE was set, ZRANGE_PRECISION would have no effect
> > and the bug would occur again.
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105396
> > CC: <mesa-stable at lists.freedesktop.org>
> > CC: Dave Airlie <airlied at redhat.com>
> > CC: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
> > CC: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> > ---
> >  src/amd/vulkan/radv_cmd_buffer.c | 52 +++++++++++++++++++++++++++++++++++++---
> >  1 file changed, 49 insertions(+), 3 deletions(-)
> > 
> > diff --git a/src/amd/vulkan/radv_cmd_buffer.c b/src/amd/vulkan/radv_cmd_buffer.c
> > index 3e0ed0e9a9..89e31a0347 100644
> > --- a/src/amd/vulkan/radv_cmd_buffer.c
> > +++ b/src/amd/vulkan/radv_cmd_buffer.c
> > @@ -915,6 +915,37 @@ radv_emit_fb_ds_state(struct radv_cmd_buffer *cmd_buffer,
> > 
> >         }
> > 
> > +       if (image->surface.htile_size)
> > +       {
> > +               /* If the last depth clear value was 0.0f, set ZRANGE_PRECISION
> > +                * to 0 in dp_z_info for more accuracy with reverse depth; and
> > +                * to avoid https://bugs.freedesktop.org/show_bug.cgi?id=105396.
> > +                * Otherwise, we leave it set to 1.
> > +                */
> > +               radeon_emit(cmd_buffer->cs, PKT3(PKT3_COND_WRITE, 7, 0));
> > +
> > +               const uint32_t write_space = 0 << 8;    /* register */
> > +               const uint32_t poll_space = 1 << 4;     /* memory */
> > +               const uint32_t function = 3 << 0;       /* equal to the reference */
> > +               const uint32_t options = write_space | poll_space | function;
> > +               radeon_emit(cmd_buffer->cs, options);
> > +
> > +               /* poll address - location of the depth clear value */
> > +               uint64_t va = radv_buffer_get_va(image->bo);
> > +               va += image->offset + image->clear_value_offset;
> > +               radeon_emit(cmd_buffer->cs, va);
> > +               radeon_emit(cmd_buffer->cs, va >> 32);
> > +
> > +               radeon_emit(cmd_buffer->cs, fui(0.0f));         /* reference value */
> > +               radeon_emit(cmd_buffer->cs, (uint32_t)-1);      /* comparison mask */
> > +               radeon_emit(cmd_buffer->cs, R_028040_DB_Z_INFO >> 2); /* write address low */
> > +               radeon_emit(cmd_buffer->cs, 0u);                /* write address high */
> > +
> > +               /* The value to write data when the condition passes */
> > +               uint32_t db_z_info_clear_zero = db_z_info & C_028040_ZRANGE_PRECISION;
> > +               radeon_emit(cmd_buffer->cs, db_z_info_clear_zero);
> > +       }
> > +
> >         radeon_set_context_reg(cmd_buffer->cs, R_028B78_PA_SU_POLY_OFFSET_DB_FMT_CNTL,
> >                                ds->pa_su_poly_offset_db_fmt_cntl);
> >  }
> > @@ -3479,7 +3510,8 @@ void radv_CmdEndRenderPass(
> > 
> >  /*
> >   * For HTILE we have the following interesting clear words:
> > - *   0xfffff30f: Uncompressed, full depth range, for depth+stencil HTILE
> > + *   0xfffff30f: Uncompressed, full depth range, for depth+stencil HTILE when ZRANGE_PRECISION is 1
> > + *   0x0003f30f: Uncompressed, full depth range, for depth+stencil HTILE when ZRANGE_PRECISION is 0
> >   *   0xfffc000f: Uncompressed, full depth range, for depth only HTILE.
> >   *   0xfffffff0: Clear depth to 1.0
> >   *   0x00000000: Clear depth to 0.0
> > @@ -3528,8 +3560,22 @@ static void radv_handle_depth_image_transition(struct radv_cmd_buffer *cmd_buffe
> >                 radv_initialize_htile(cmd_buffer, image, range, 0);
> >         } else if (!radv_layout_is_htile_compressed(image, src_layout, src_queue_mask) &&
> >                    radv_layout_is_htile_compressed(image, dst_layout, dst_queue_mask)) {
> > -               uint32_t clear_value = vk_format_is_stencil(image->vk_format) ? 0xfffff30f : 0xfffc000f;
> > -               radv_initialize_htile(cmd_buffer, image, range, clear_value);
> > +               if (vk_format_is_stencil(image->vk_format)) {
> > +                       /* The appropriate clear value depends on DB_Z_INFO's
> > +                        * ZRANGE_PRECISION, which can vary depending on the
> > +                        * last used clear value, which could be from another
> > +                        * command buffer. Instead of picking the appropriate
> > +                        * clear value on the GPU, resummarize accurately.
> > +                        */
> > +                       VkImageSubresourceRange local_range = *range;
> > +                       local_range.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
> > +                       local_range.baseMipLevel = 0;
> > +                       local_range.levelCount = 1;
> > +
> > +                       radv_resummarize_depth_image_inplace(cmd_buffer, image, &local_range);
> 
> Can we instead of resummarizing, just do the reset + write the clear words?

That would be fine. I used a resummarize as it was already implemented
and I wasn't confident I would get the clearing implementation right.

> Otherwise looks good to me, please tell if I should do it. I'd do it
> in a follow up patch, except this is nominated to stable.

If you wouldn't mind, that would be great.

> Apologies for the delay.

No problem.

> 
> > +               } else {
> > +                       radv_initialize_htile(cmd_buffer, image, range, 0xfffc000f);
> > +               }
> >         } else if (radv_layout_is_htile_compressed(image, src_layout, src_queue_mask) &&
> >                    !radv_layout_is_htile_compressed(image, dst_layout, dst_queue_mask)) {
> >                 VkImageSubresourceRange local_range = *range;
> > --
> > 2.14.3
> >