[PATCH] Revert "drm/amd/display: ignore modifiers when checking for format support"

[Bas Nieuwenhuizen]

This reverts commit 5089c4a8ebea3c3ad9eedf038dad7098ebc06131.

This breaks validation and enumeration of display capable modifiers.

The early return true means the rest of the validation code never gets
executed, and we need that to enumerate the right modifiers to userspace
for the format.

The modifiers that are in the initial list generated for a plane are the
superset for all formats and we need the proper checks in this function
to filter some of them out for formats with which they're invalid to be
used.

Furthermore, the safety contract here is that we validate the incoming
modifiers to ensure the kernel can handle them and the display hardware
can handle them. This includes e.g. rejecting multi-plane images with DCC.

Note that the legacy swizzle mechanism allows encoding more swizzles, and
at fb creation time we convert them to modifiers and reject those with
no corresponding modifiers. If we are seeing rejections I'm happy to
help define modifiers that correspond to those, or if absolutely needed
implement a fallback path to allow for less strict validation of the
legacy path.

However, I'd like to revert this patch, since any of these is going to
be a significant rework of the patch, and I'd rather not the regression
gets into a release or forgotten in the meantime.

Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 53 +++----------------
 1 file changed, 7 insertions(+), 46 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 60fb99b74713..698741fd39f4 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4936,7 +4936,8 @@ 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;
 
 	if (!info)
@@ -4952,53 +4953,13 @@ static bool dm_plane_format_mod_supported(struct drm_plane *plane,
 		return true;
 	}
 
-	/* 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:
-			/* asics before AI 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 */
+	/* 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])
 			break;
 	}
+	if (i == plane->modifier_count)
+		return false;
 
 	/*
 	 * For D swizzle the canonical modifier depends on the bpp, so check
-- 
2.36.1