drm: introduce fb_modifiers_not_supported flag in mode_config

If only linear modifier is advertised, since there are many drivers that
only linear supported, the DRM core should handle this rather than
open-coding in every driver. However, there are legacy drivers such as
radeon that do not support modifiers but infer the actual layout of the
underlying buffer. Therefore, a new flag fb_modifiers_not_supported is
introduced for these legacy drivers, and allow_fb_modifiers is replaced
with this new flag.

v3:
 - change the order as follows:
   1. add fb_modifiers_not_supported flag
   2. add default modifiers
   3. remove allow_fb_modifiers flag
 - add a conditional disable in amdgpu_dm_plane_init()

v4:
 - modify kernel docs

v5:
 - modify kernel docs

Signed-off-by: Tomohito Esaki <etom@igel.co.jp>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220128060836.11216-2-etom@igel.co.jp

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 07f5abc875e9..4562a8b86579 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -309,7 +309,7 @@ drm_internal_framebuffer_create(struct drm_device *dev,
 	}
 
 	if (r->flags & DRM_MODE_FB_MODIFIERS &&
-	    !dev->mode_config.allow_fb_modifiers) {
+	    dev->mode_config.fb_modifiers_not_supported) {
 		DRM_DEBUG_KMS("driver does not support fb modifiers\n");
 		return ERR_PTR(-EINVAL);
 	}
@@ -594,7 +594,7 @@ int drm_mode_getfb2_ioctl(struct drm_device *dev,
 	r->pixel_format = fb->format->format;
 
 	r->flags = 0;
-	if (dev->mode_config.allow_fb_modifiers)
+	if (!dev->mode_config.fb_modifiers_not_supported)
 		r->flags |= DRM_MODE_FB_MODIFIERS;
 
 	for (i = 0; i < ARRAY_SIZE(r->handles); i++) {
@@ -607,7 +607,7 @@ int drm_mode_getfb2_ioctl(struct drm_device *dev,
 	for (i = 0; i < fb->format->num_planes; i++) {
 		r->pitches[i] = fb->pitches[i];
 		r->offsets[i] = fb->offsets[i];
-		if (dev->mode_config.allow_fb_modifiers)
+		if (!dev->mode_config.fb_modifiers_not_supported)
 			r->modifier[i] = fb->modifier;
 	}