drm/amdgpu: Ensure that the modifier requested is supported by plane.

On initializing the framebuffer, call drm_any_plane_has_format to do a
check if the modifier is supported. drm_any_plane_has_format calls
dm_plane_format_mod_supported which is extended to validate that the
modifier is on the list of the plane's supported modifiers.

The bug was caught using igt-gpu-tools test: kms_addfb_basic.addfb25-bad-modifier

Tested on ChromeOS Zork by turning on the display, running an overlay
test, and running a YT video.

=== Changes from v1 ===
Explicitly handle DRM_FORMAT_MOD_INVALID modifier.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 9a2f811..2e622c1 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -908,6 +908,19 @@ int amdgpu_display_gem_fb_verify_and_init(
                                         &amdgpu_fb_funcs);
        if (ret)
                goto err;
+       /* Verify that the modifier is supported. */
+       if (!drm_any_plane_has_format(dev, mode_cmd->pixel_format,
+                                     mode_cmd->modifier[0])) {
+               struct drm_format_name_buf format_name;
+               drm_dbg_kms(dev,
+                           "unsupported pixel format %s / modifier 0x%llx\n",
+                           drm_get_format_name(mode_cmd->pixel_format,
+                                               &format_name),
+                           mode_cmd->modifier[0]);
+
+               ret = -EINVAL;
+               goto err;
+       }
 
        ret = amdgpu_display_framebuffer_init(dev, rfb, mode_cmd, obj);
        if (ret)

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 281661f..81565e7 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4210,6 +4210,7 @@ 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);
+       int i;
 
        enum dm_micro_swizzle microtile = modifier_gfx9_swizzle_mode(modifier) & 3;
 
@@ -4217,11 +4218,22 @@ static bool dm_plane_format_mod_supported(struct drm_plane *plane,
                return false;
 
        /*
-        * We always have to allow this modifier, because core DRM still
-        * checks LINEAR support if userspace does not provide modifers.
+        * We always have to allow these modifiers:
+        * 1. Core DRM checks for LINEAR support if userspace does not provide modifiers.
+        * 2. Not passing any modifiers is the same as explicitly passing INVALID.
         */
-       if (modifier == DRM_FORMAT_MOD_LINEAR)
+       if (modifier == DRM_FORMAT_MOD_LINEAR ||
+           modifier == DRM_FORMAT_MOD_INVALID) {
                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])
+                       break;
+       }
+       if (i == plane->modifier_count)
+               return false;
 
        /*
         * The arbitrary tiling support for multiplane formats has not been hooked