drm/omap: 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.

For the fbdev case a manual drm_get_format_info() lookup
is needed.

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

Due to the absence of this change in the patchset at Link:, after the
Fixed: commit below, omap_framebuffer_init() ->
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: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Fixes: 41ab92d ("drm: Make passing of format info to drm_helper_mode_fill_fb_struct() mandatory")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/98b3a62c-91ff-4f91-a58b-e1265f84180b@sirena.org.uk
Link: https://lore.kernel.org/all/20250701090722.13645-1-ville.syrjala@linux.intel.com
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20250805175752.690504-2-imre.deak@intel.com

Author: ideak

drivers/gpu/drm/omapdrm/omap_fb.c

@@ -351,7 +351,7 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
 		}
 	}
 
-	fb = omap_framebuffer_init(dev, mode_cmd, bos);
+	fb = omap_framebuffer_init(dev, info, mode_cmd, bos);
 	if (IS_ERR(fb))
 		goto error;
 
@@ -365,9 +365,9 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
 }
 
 struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
+		const struct drm_format_info *info,
 		const struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos)
 {
-	const struct drm_format_info *format = NULL;
 	struct omap_framebuffer *omap_fb = NULL;
 	struct drm_framebuffer *fb = NULL;
 	unsigned int pitch = mode_cmd->pitches[0];
@@ -377,15 +377,12 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 			dev, mode_cmd, mode_cmd->width, mode_cmd->height,
 			(char *)&mode_cmd->pixel_format);
 
-	format = drm_get_format_info(dev, mode_cmd->pixel_format,
-				     mode_cmd->modifier[0]);
-
 	for (i = 0; i < ARRAY_SIZE(formats); i++) {
 		if (formats[i] == mode_cmd->pixel_format)
 			break;
 	}
 
-	if (!format || i == ARRAY_SIZE(formats)) {
+	if (i == ARRAY_SIZE(formats)) {
 		dev_dbg(dev->dev, "unsupported pixel format: %4.4s\n",
 			(char *)&mode_cmd->pixel_format);
 		ret = -EINVAL;
@@ -399,31 +396,31 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 	}
 
 	fb = &omap_fb->base;
-	omap_fb->format = format;
+	omap_fb->format = info;
 	mutex_init(&omap_fb->lock);
 
 	/*
 	 * The code below assumes that no format use more than two planes, and
 	 * that the two planes of multiplane formats need the same number of
 	 * bytes per pixel.
 	 */
-	if (format->num_planes == 2 && pitch != mode_cmd->pitches[1]) {
+	if (info->num_planes == 2 && pitch != mode_cmd->pitches[1]) {
 		dev_dbg(dev->dev, "pitches differ between planes 0 and 1\n");
 		ret = -EINVAL;
 		goto fail;
 	}
 
-	if (pitch % format->cpp[0]) {
+	if (pitch % info->cpp[0]) {
 		dev_dbg(dev->dev,
 			"buffer pitch (%u bytes) is not a multiple of pixel size (%u bytes)\n",
-			pitch, format->cpp[0]);
+			pitch, info->cpp[0]);
 		ret = -EINVAL;
 		goto fail;
 	}
 
-	for (i = 0; i < format->num_planes; i++) {
+	for (i = 0; i < info->num_planes; i++) {
 		struct plane *plane = &omap_fb->planes[i];
-		unsigned int vsub = i == 0 ? 1 : format->vsub;
+		unsigned int vsub = i == 0 ? 1 : info->vsub;
 		unsigned int size;
 
 		size = pitch * mode_cmd->height / vsub;
@@ -440,7 +437,7 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 		plane->dma_addr  = 0;
 	}
 
-	drm_helper_mode_fill_fb_struct(dev, fb, NULL, mode_cmd);
+	drm_helper_mode_fill_fb_struct(dev, fb, info, mode_cmd);
 
 	ret = drm_framebuffer_init(dev, fb, &omap_framebuffer_funcs);
 	if (ret) {

drivers/gpu/drm/omapdrm/omap_fb.h

@@ -13,6 +13,7 @@ struct drm_connector;
 struct drm_device;
 struct drm_file;
 struct drm_framebuffer;
+struct drm_format_info;
 struct drm_gem_object;
 struct drm_mode_fb_cmd2;
 struct drm_plane_state;
@@ -23,6 +24,7 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
 		struct drm_file *file, const struct drm_format_info *info,
 		const struct drm_mode_fb_cmd2 *mode_cmd);
 struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
+		const struct drm_format_info *info,
 		const struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos);
 int omap_framebuffer_pin(struct drm_framebuffer *fb);
 void omap_framebuffer_unpin(struct drm_framebuffer *fb);

drivers/gpu/drm/omapdrm/omap_fbdev.c

@@ -197,7 +197,10 @@ int omap_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
 		goto fail;
 	}
 
-	fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
+	fb = omap_framebuffer_init(dev,
+				   drm_get_format_info(dev, mode_cmd.pixel_format,
+						       mode_cmd.modifier[0]),
+				   &mode_cmd, &bo);
 	if (IS_ERR(fb)) {
 		dev_err(dev->dev, "failed to allocate fb\n");
 		/* note: if fb creation failed, we can't rely on fb destroy