[Mesa-dev] [Nouveau] [PATCH mesa 1/4] nv30: Fix creation of scanout buffers

[Ilia Mirkin]

On Thu, Sep 3, 2015 at 7:25 AM, Hans de Goede <hdegoede at redhat.com> wrote:
> Scanout buffers on nv30 must always be non-swizzled and have special
> width alignment constraints.
>
> These constrains have been taken from the xf86-video-nouveau
> src/nv_accel_common.c: nouveau_allocate_surface() function.
>
> nouveau_allocate_surface() applies these width constraints only when a
> tiled attribute is set, which it sets for all surfaces allocated via
> dri, and this "tiling" is not the same as swizzling, scanout surfaces
> must be linear / have a uniform_pitch or only complete garbage is shown.

I think the deal is that it's actually not tiling at all. There's no
"other" tiling (esp not on pre-tesla). Hence the confusion. The
nouveau driver does indeed do

PUSH_DATA (push, NV30_3D_RT_FORMAT_TYPE_LINEAR |
NV30_3D_RT_FORMAT_ZETA_Z24S8 | fmt->card_fmt);

without OR'ing in the log2(w/h). So this looks good. I wondered how it
worked at all with swizzling. I guess it didn't :)

Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: "10.6 11.0" <mesa-stable at lists.freedesktop.org>

[by the way, having a git branch where I can pull these from would
definitely *not* slow down the speed with which I push these out to
master...]

>
> This commit fixes dri3 on nv30 showing a garbled display, with dri3 the
> scanout buffers are allocated by mesa, rather then by the ddx, and the
> wrong stride of these buffers was causing the garbled display.
>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  src/gallium/drivers/nouveau/nv30/nv30_miptree.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/src/gallium/drivers/nouveau/nv30/nv30_miptree.c b/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
> index c75b4b9..2276347 100644
> --- a/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
> +++ b/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
> @@ -28,6 +28,7 @@
>  #include "util/u_surface.h"
>
>  #include "nv_m2mf.xml.h"
> +#include "nv_object.xml.h"
>  #include "nv30/nv30_screen.h"
>  #include "nv30/nv30_context.h"
>  #include "nv30/nv30_resource.h"
> @@ -362,6 +363,7 @@ nv30_miptree_create(struct pipe_screen *pscreen,
>     blocksz = util_format_get_blocksize(pt->format);
>
>     if ((pt->target == PIPE_TEXTURE_RECT) ||
> +       (pt->bind & PIPE_BIND_SCANOUT) ||
>         !util_is_power_of_two(pt->width0) ||
>         !util_is_power_of_two(pt->height0) ||
>         !util_is_power_of_two(pt->depth0) ||
> @@ -369,6 +371,14 @@ nv30_miptree_create(struct pipe_screen *pscreen,
>         util_format_is_float(pt->format) || mt->ms_mode) {
>        mt->uniform_pitch = util_format_get_nblocksx(pt->format, w) * blocksz;
>        mt->uniform_pitch = align(mt->uniform_pitch, 64);
> +      if (pt->bind & PIPE_BIND_SCANOUT) {
> +         struct nv30_screen *screen = nv30_screen(pscreen);
> +         int pitch_align = MAX2(
> +               screen->eng3d->oclass >= NV40_3D_CLASS ? 1024 : 256,
> +               /* round_down_pow2(mt->uniform_pitch / 4) */
> +               1 << (util_last_bit(mt->uniform_pitch / 4) - 1));
> +         mt->uniform_pitch = align(mt->uniform_pitch, pitch_align);
> +      }
>     }
>
>     if (!mt->uniform_pitch)
> --
> 2.4.3
>
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