drm/simpledrm: Compute linestride with drm_format_info_min_pitch()

If not given, compute the stride with drm_format_info_min_pitch(). It's
the standard helper for this purpose.
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: fd9e3169 ("drm/simpledrm: Compute framebuffer stride if not set")
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220922130944.27138-2-tzimmermann@suse.de

drivers/gpu/drm/tiny/simpledrm.c

@@ -687,8 +687,11 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
 		drm_err(dev, "no simplefb configuration found\n");
 		return ERR_PTR(-ENODEV);
 	}
-	if (!stride)
-		stride = DIV_ROUND_UP(drm_format_info_bpp(format, 0) * width, 8);
+	if (!stride) {
+		stride = drm_format_info_min_pitch(format, 0, width);
+		if (drm_WARN_ON(dev, !stride))
+			return ERR_PTR(-EINVAL);
+	}
 
 	sdev->mode = simpledrm_mode(width, height);
 	sdev->format = format;