On Fri, Jul 17, 2020 at 11:57:57AM -0700, James Jones wrote:
> Accept the DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK()
> family of modifiers to handle broken userspace
> Xorg modesetting and Mesa drivers.
>
> Tested with Xorg 1.20 modesetting driver,
> weston@c46c70dac84a4b3030cd05b380f9f410536690fc,
> gnome & KDE wayland desktops from Ubuntu 18.04,
> and sway 1.5
Just bikeshed, but maybe a few more words on what exactly is broken and
how this works around it. Specifically why we only accept these, but don't
advertise them.
>
> Signed-off-by: James Jones <jajones@xxxxxxxxxx>
Needs Fixes: line here. Also nice to mention the bug reporter/link.
> ---
> drivers/gpu/drm/nouveau/nouveau_display.c | 26 +++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
> index 496c4621cc78..31543086254b 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_display.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_display.c
> @@ -191,8 +191,14 @@ nouveau_decode_mod(struct nouveau_drm *drm,
> uint32_t *tile_mode,
> uint8_t *kind)
> {
> + struct nouveau_display *disp = nouveau_display(drm->dev);
> BUG_ON(!tile_mode || !kind);
>
> + if ((modifier & (0xffull << 12)) == 0ull) {
> + /* Legacy modifier. Translate to this device's 'kind.' */
> + modifier |= disp->format_modifiers[0] & (0xffull << 12);
> + }
Hm I tried to understand what this magic does by looking at drm_fourcc.h,
but the drm_fourcc_canonicalize_nvidia_format_mod() in there implements
something else. Is that function wrong, or should we use it here instead?
Or is there something else going on entirely?
Cheers, Daniel
> +
> if (modifier == DRM_FORMAT_MOD_LINEAR) {
> /* tile_mode will not be used in this case */
> *tile_mode = 0;
> @@ -227,6 +233,16 @@ nouveau_framebuffer_get_layout(struct drm_framebuffer *fb,
> }
> }
>
> +static const u64 legacy_modifiers[] = {
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(0),
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(1),
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(2),
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(3),
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(4),
> + DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(5),
> + DRM_FORMAT_MOD_INVALID
> +};
> +
> static int
> nouveau_validate_decode_mod(struct nouveau_drm *drm,
> uint64_t modifier,
> @@ -247,8 +263,14 @@ nouveau_validate_decode_mod(struct nouveau_drm *drm,
> (disp->format_modifiers[mod] != modifier);
> mod++);
>
> - if (disp->format_modifiers[mod] == DRM_FORMAT_MOD_INVALID)
> - return -EINVAL;
> + if (disp->format_modifiers[mod] == DRM_FORMAT_MOD_INVALID) {
> + for (mod = 0;
> + (legacy_modifiers[mod] != DRM_FORMAT_MOD_INVALID) &&
> + (legacy_modifiers[mod] != modifier);
> + mod++);
> + if (legacy_modifiers[mod] == DRM_FORMAT_MOD_INVALID)
> + return -EINVAL;
> + }
>
> nouveau_decode_mod(drm, modifier, tile_mode, kind);
>
> --
> 2.17.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
