We can reject invalid modifiers elsewhere, but it can't be here because
it's also the non-modifier path.
We expose 256KB_R_X or 64KB_R_X modifiers depending on chip-specific
settings, but not both. Only the optimal option is exposed. This is OK for
modifiers, but not OK with AMD-specific BO metadata where the UMD
determines the swizzle mode.
Marek
On Tue, Jun 14, 2022 at 8:38 PM Bas Nieuwenhuizen <b...@basnieuwenhuizen.nl>
wrote:
> On Mon, Jun 13, 2022 at 1:47 PM Marek Olšák <mar...@gmail.com> wrote:
> >
> > Bas, the code was literally rejecting swizzle modes that were not in the
> modifier list, which was incorrect. That's because the modifier list is a
> subset of all supported swizzle modes.
>
> That was WAI. The kernel is now in charge of rejecting stuff that is
> not capable of being displayed.
>
> Allowing all in format_mod_supported has several implications on
> exposed & accepted modifiers as well, that should be avoided even if
> we should do a behavior change for non-modifiers: We now expose (i.e.
> list) modifiers for formats which they don't support and we removed
> the check that the modifier is in the list for commits with modifiers
> too. Hence this logic would need a serious rework instead of the patch
> that was sent.
>
> What combinations were failing, and can't we just add modifiers for them?
>
>
>
>
> >
> > Marek
> >
> > On Sun, Jun 12, 2022 at 7:54 PM Bas Nieuwenhuizen <
> b...@basnieuwenhuizen.nl> wrote:
> >>
> >> On Thu, Jun 9, 2022 at 4:27 PM Aurabindo Pillai
> >> <aurabindo.pil...@amd.com> wrote:
> >> >
> >> > [Why&How]
> >> > There are cases where swizzle modes are set but modifiers arent. For
> >> > such a userspace, we need not check modifiers while checking
> >> > compatibilty in the drm hook for checking plane format.
> >> >
> >> > Ignore checking modifiers but check the DCN generation for the
> >> > supported swizzle mode.
> >> >
> >> > Signed-off-by: Aurabindo Pillai <aurabindo.pil...@amd.com>
> >> > ---
> >> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 51
> +++++++++++++++++--
> >> > 1 file changed, 46 insertions(+), 5 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> >> > index 2023baf41b7e..1322df491736 100644
> >> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> >> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> >> > @@ -4938,6 +4938,7 @@ static bool
> dm_plane_format_mod_supported(struct drm_plane *plane,
> >> > {
> >> > struct amdgpu_device *adev = drm_to_adev(plane->dev);
> >> > const struct drm_format_info *info = drm_format_info(format);
> >> > + struct hw_asic_id asic_id = adev->dm.dc->ctx->asic_id;
> >> > int i;
> >> >
> >> > enum dm_micro_swizzle microtile =
> modifier_gfx9_swizzle_mode(modifier) & 3;
> >> > @@ -4955,13 +4956,53 @@ static bool
> dm_plane_format_mod_supported(struct drm_plane *plane,
> >> > return true;
> >> > }
> >> >
> >> > - /* Check that the modifier is on the list of the plane's
> supported modifiers. */
> >> > - for (i = 0; i < plane->modifier_count; i++) {
> >> > - if (modifier == plane->modifiers[i])
> >> > + /* check if swizzle mode is supported by this version of DCN
> */
> >> > + switch (asic_id.chip_family) {
> >> > + case FAMILY_SI:
> >> > + case FAMILY_CI:
> >> > + case FAMILY_KV:
> >> > + case FAMILY_CZ:
> >> > + case FAMILY_VI:
> >> > + /* AI and earlier asics does not have
> modifier support */
> >> > + return false;
> >> > + break;
> >> > + case FAMILY_AI:
> >> > + case FAMILY_RV:
> >> > + case FAMILY_NV:
> >> > + case FAMILY_VGH:
> >> > + case FAMILY_YELLOW_CARP:
> >> > + case AMDGPU_FAMILY_GC_10_3_6:
> >> > + case AMDGPU_FAMILY_GC_10_3_7:
> >> > + switch (AMD_FMT_MOD_GET(TILE, modifier)) {
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_R_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_D_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_S_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_D:
> >> > + return true;
> >> > + break;
> >> > + default:
> >> > + return false;
> >> > + break;
> >> > + }
> >> > + break;
> >> > + case AMDGPU_FAMILY_GC_11_0_0:
> >> > + switch (AMD_FMT_MOD_GET(TILE, modifier)) {
> >> > + case AMD_FMT_MOD_TILE_GFX11_256K_R_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_R_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_D_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_S_X:
> >> > + case AMD_FMT_MOD_TILE_GFX9_64K_D:
> >> > + return true;
> >> > + break;
> >> > + default:
> >> > + return false;
> >> > + break;
> >> > + }
> >> > + break;
> >> > + default:
> >> > + ASSERT(0); /* Unknown asic */
> >> > break;
> >> > }
> >>
> >> This seems broken to me. AFAICT we always return in the switch so the
> >> code after this that checks for valid DCC usage isn't executed.
> >> Checking the list of modifiers is also essential to make sure other
> >> stuff in the modifier is set properly.
> >>
> >> If you have userspace that is not using modifiers that is giving you
> >> issues, a better place to look might be
> >> convert_tiling_flags_to_modifier in amdgpu_display.c
> >>
> >> > - if (i == plane->modifier_count)
> >> > - return false;
> >> >
> >> > /*
> >> > * For D swizzle the canonical modifier depends on the bpp,
> so check
> >> > --
> >> > 2.36.1
> >> >
>
