Re: [RFC PATCH v3 1/3] drm: introduce fb_modifiers_not_supported flag in mode_config

Esaki Tomohito <etom@xxxxxxxxxx> · Tue, 25 Jan 2022 14:19:40 +0900

Hello Laurent-san

Thank you for your reviews and advices.

I'll fix this patch series following your advice.

Thanks,
Esaki

On 2022/01/24 7:50, Laurent Pinchart wrote:
Hello Esaki-san,

On Fri, Jan 14, 2022 at 07:17:51PM +0900, Tomohito Esaki wrote:
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.

Signed-off-by: Tomohito Esaki <etom@xxxxxxxxxx>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_display.c       |  6 +++---
  drivers/gpu/drm/amd/amdgpu/dce_v10_0.c            |  2 ++
  drivers/gpu/drm/amd/amdgpu/dce_v11_0.c            |  2 ++
  drivers/gpu/drm/amd/amdgpu/dce_v6_0.c             |  1 +
  drivers/gpu/drm/amd/amdgpu/dce_v8_0.c             |  2 ++
  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  3 +++
  drivers/gpu/drm/drm_framebuffer.c                 |  6 +++---
  drivers/gpu/drm/drm_ioctl.c                       |  2 +-
  drivers/gpu/drm/nouveau/nouveau_display.c         |  6 ++++--
  drivers/gpu/drm/radeon/radeon_display.c           |  2 ++
  include/drm/drm_mode_config.h                     | 10 ++++++++++
  11 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 82011e75ed85..edbb30d47b8c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -954,7 +954,7 @@ static int amdgpu_display_verify_sizes(struct amdgpu_framebuffer *rfb)
  	int ret;
  	unsigned int i, block_width, block_height, block_size_log2;
  
-	if (!rfb->base.dev->mode_config.allow_fb_modifiers)
+	if (rfb->base.dev->mode_config.fb_modifiers_not_supported)
  		return 0;
  
  	for (i = 0; i < format_info->num_planes; ++i) {
@@ -1141,7 +1141,7 @@ int amdgpu_display_framebuffer_init(struct drm_device *dev,
  	if (ret)
  		return ret;
  
-	if (!dev->mode_config.allow_fb_modifiers) {
+	if (dev->mode_config.fb_modifiers_not_supported) {
  		drm_WARN_ONCE(dev, adev->family >= AMDGPU_FAMILY_AI,
  			      "GFX9+ requires FB check based on format modifier\n");
  		ret = check_tiling_flags_gfx6(rfb);
@@ -1149,7 +1149,7 @@ int amdgpu_display_framebuffer_init(struct drm_device *dev,
  			return ret;
  	}
  
-	if (dev->mode_config.allow_fb_modifiers &&
+	if (!dev->mode_config.fb_modifiers_not_supported &&
  	    !(rfb->base.flags & DRM_MODE_FB_MODIFIERS)) {
  		ret = convert_tiling_flags_to_modifier(rfb);
  		if (ret) {
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index d1570a462a51..fb61c0814115 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -2798,6 +2798,8 @@ static int dce_v10_0_sw_init(void *handle)
  	adev_to_drm(adev)->mode_config.preferred_depth = 24;
  	adev_to_drm(adev)->mode_config.prefer_shadow = 1;
  
+	adev_to_drm(adev)->mode_config.fb_modifiers_not_supported = true;
+
  	adev_to_drm(adev)->mode_config.fb_base = adev->gmc.aper_base;
  
  	r = amdgpu_display_modeset_create_props(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
index 18a7b3bd633b..17942a11366d 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -2916,6 +2916,8 @@ static int dce_v11_0_sw_init(void *handle)
  	adev_to_drm(adev)->mode_config.preferred_depth = 24;
  	adev_to_drm(adev)->mode_config.prefer_shadow = 1;
  
+	adev_to_drm(adev)->mode_config.fb_modifiers_not_supported = true;
+
  	adev_to_drm(adev)->mode_config.fb_base = adev->gmc.aper_base;
  
  	r = amdgpu_display_modeset_create_props(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
index c7803dc2b2d5..2ec99ec8e1a3 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
@@ -2674,6 +2674,7 @@ static int dce_v6_0_sw_init(void *handle)
  	adev_to_drm(adev)->mode_config.max_height = 16384;
  	adev_to_drm(adev)->mode_config.preferred_depth = 24;
  	adev_to_drm(adev)->mode_config.prefer_shadow = 1;
+	adev_to_drm(adev)->mode_config.fb_modifiers_not_supported = true;
  	adev_to_drm(adev)->mode_config.fb_base = adev->gmc.aper_base;
  
  	r = amdgpu_display_modeset_create_props(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 8318ee8339f1..de11fbe5aba2 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -2695,6 +2695,8 @@ static int dce_v8_0_sw_init(void *handle)
  	adev_to_drm(adev)->mode_config.preferred_depth = 24;
  	adev_to_drm(adev)->mode_config.prefer_shadow = 1;
  
+	adev_to_drm(adev)->mode_config.fb_modifiers_not_supported = true;
+
  	adev_to_drm(adev)->mode_config.fb_base = adev->gmc.aper_base;
  
  	r = amdgpu_display_modeset_create_props(adev);
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 2f0b14f8f833..61cb41766fae 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7868,6 +7868,9 @@ static int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm,
  	if (res)
  		return res;
  
+	if (modifiers == NULL)
+		adev_to_drm(dm->adev)->mode_config.fb_modifiers_not_supported = true;
+
  	res = drm_universal_plane_init(adev_to_drm(dm->adev), plane, possible_crtcs,
  				       &dm_plane_funcs, formats, num_formats,
  				       modifiers, plane->type, NULL);
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;
  	}
  
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 8b8744dcf691..51fcf1298023 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -297,7 +297,7 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
  			req->value = 64;
  		break;
  	case DRM_CAP_ADDFB2_MODIFIERS:
-		req->value = dev->mode_config.allow_fb_modifiers;
+		req->value = !dev->mode_config.fb_modifiers_not_supported;
  		break;
  	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
  		req->value = 1;
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index 2b460835a438..2cd0932b3d68 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -708,10 +708,12 @@ nouveau_display_create(struct drm_device *dev)
  				     &disp->disp);
  		if (ret == 0) {
  			nouveau_display_create_properties(dev);
-			if (disp->disp.object.oclass < NV50_DISP)
+			if (disp->disp.object.oclass < NV50_DISP) {
+				dev->mode_config.fb_modifiers_not_supported = true;
  				ret = nv04_display_create(dev);
-			else
+			} else {
  				ret = nv50_display_create(dev);
+			}
  		}
  	} else {
  		ret = 0;
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 573154268d43..b9a07677a71e 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -1596,6 +1596,8 @@ int radeon_modeset_init(struct radeon_device *rdev)
  	rdev->ddev->mode_config.preferred_depth = 24;
  	rdev->ddev->mode_config.prefer_shadow = 1;
  
+	rdev->ddev->mode_config.fb_modifiers_not_supported = true;
+
  	rdev->ddev->mode_config.fb_base = rdev->mc.aper_base;
  
  	ret = radeon_modeset_create_props(rdev);
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 91ca575a78de..da82f45351c7 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -933,6 +933,16 @@ struct drm_mode_config {
  	 */
  	bool allow_fb_modifiers;
  
+	/**
+	 * @fb_modifiers_not_supported:
+	 *
+	 * This flag is for legacy drivers such as radeon that do not support
+	 * modifiers but infer the actual layout of the underlying buffer.
+	 * Generally, each drivers must support modifiers, this flag should not
+	 * be set.

I'd write it a bit differently, to explain what the flag does:

	 * When this flag is set, the DRM device will not expose modifier
	 * support to userspace. This is only used by legacy drivers (such as
	 * radeon) that infer the buffer layout through heuristics without using
	 * modifiers. New drivers shall not set fhis flag.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

+	 */
+	bool fb_modifiers_not_supported;
+
  	/**
  	 * @normalize_zpos:
  	 *







