drm/nouveau: Pass along the format info from .fb_create() to drm_helper_mode_fill_fb_struct()

Plumb the format info from .fb_create() all the way to
drm_helper_mode_fill_fb_struct() to avoid the redundant
lookup.

The patch is based on the driver parts of the patchset at Link:
below, which missed converting the nouveau driver.

Due to the absence of this change in the patchset at Link:, after the
Fixed: commit below, nouveau_framebuffer_new() ->
drm_helper_mode_fill_fb_struct() set drm_framebuffer::format incorrectly
to NULL, which lead to the !fb->format WARN() in drm_framebuffer_init()
and causing framebuffer creation to fail. This patch fixes both of these
issues.

v2: Amend the commit log mentioning the functional issues the patch
    fixes. (Tomi)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: nouveau@lists.freedesktop.org
Fixes: 41ab92d ("drm: Make passing of format info to drm_helper_mode_fill_fb_struct() mandatory")
Link: https://lore.kernel.org/all/20250701090722.13645-1-ville.syrjala@linux.intel.com
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: James Jones <jajones@nvidia.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: James Jones <jajones@nvidia.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20250805175752.690504-3-imre.deak@intel.com

Author: ideak

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -253,14 +253,14 @@ nouveau_check_bl_size(struct nouveau_drm *drm, struct nouveau_bo *nvbo,
 
 int
 nouveau_framebuffer_new(struct drm_device *dev,
+			const struct drm_format_info *info,
 			const struct drm_mode_fb_cmd2 *mode_cmd,
 			struct drm_gem_object *gem,
 			struct drm_framebuffer **pfb)
 {
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_bo *nvbo = nouveau_gem_object(gem);
 	struct drm_framebuffer *fb;
-	const struct drm_format_info *info;
 	unsigned int height, i;
 	uint32_t tile_mode;
 	uint8_t kind;
@@ -295,9 +295,6 @@ nouveau_framebuffer_new(struct drm_device *dev,
 		kind = nvbo->kind;
 	}
 
-	info = drm_get_format_info(dev, mode_cmd->pixel_format,
-				   mode_cmd->modifier[0]);
-
 	for (i = 0; i < info->num_planes; i++) {
 		height = drm_format_info_plane_height(info,
 						      mode_cmd->height,
@@ -321,7 +318,7 @@ nouveau_framebuffer_new(struct drm_device *dev,
 	if (!(fb = *pfb = kzalloc(sizeof(*fb), GFP_KERNEL)))
 		return -ENOMEM;
 
-	drm_helper_mode_fill_fb_struct(dev, fb, NULL, mode_cmd);
+	drm_helper_mode_fill_fb_struct(dev, fb, info, mode_cmd);
 	fb->obj[0] = gem;
 
 	ret = drm_framebuffer_init(dev, fb, &nouveau_framebuffer_funcs);
@@ -344,7 +341,7 @@ nouveau_user_framebuffer_create(struct drm_device *dev,
 	if (!gem)
 		return ERR_PTR(-ENOENT);
 
-	ret = nouveau_framebuffer_new(dev, mode_cmd, gem, &fb);
+	ret = nouveau_framebuffer_new(dev, info, mode_cmd, gem, &fb);
 	if (ret == 0)
 		return fb;
 

drivers/gpu/drm/nouveau/nouveau_display.h

@@ -8,8 +8,11 @@
 
 #include <drm/drm_framebuffer.h>
 
+struct drm_format_info;
+
 int
 nouveau_framebuffer_new(struct drm_device *dev,
+			const struct drm_format_info *info,
 			const struct drm_mode_fb_cmd2 *mode_cmd,
 			struct drm_gem_object *gem,
 			struct drm_framebuffer **pfb);