drm/fbdev-helper: Remove drm_fb_helper_debug_enter/_leave()

Remove the debug_enter/debug_leave helpers, as there are no DRM
drivers supporting debugging with kgdb. Remove code to keep track
of existing fbdev-emulation state. None of this required any longer.

Also remove mode_set_base_atomic from struct drm_crtc_helper_funcs,
which has no callers or implementations.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20251125130634.1080966-5-tzimmermann@suse.de

3 files changed, 0 insertions, 152 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index be790fc68707..49a84396b440 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -77,9 +77,6 @@ MODULE_PARM_DESC(drm_leak_fbdev_smem,
 		 "Allow unsafe leaking fbdev physical smem address [default=false]");
 #endif
 
-static LIST_HEAD(kernel_fb_helper_list);
-static DEFINE_MUTEX(kernel_fb_helper_lock);
-
 /**
  * DOC: fbdev helpers
  *
@@ -117,101 +114,6 @@ static DEFINE_MUTEX(kernel_fb_helper_lock);
  * mmap page writes.
  */
 
-static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
-{
-	uint16_t *r_base, *g_base, *b_base;
-
-	if (crtc->funcs->gamma_set == NULL)
-		return;
-
-	r_base = crtc->gamma_store;
-	g_base = r_base + crtc->gamma_size;
-	b_base = g_base + crtc->gamma_size;
-
-	crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
-			       crtc->gamma_size, NULL);
-}
-
-/**
- * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
- * @info: fbdev registered by the helper
- */
-int drm_fb_helper_debug_enter(struct fb_info *info)
-{
-	struct drm_fb_helper *helper = info->par;
-	const struct drm_crtc_helper_funcs *funcs;
-	struct drm_mode_set *mode_set;
-
-	list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
-		mutex_lock(&helper->client.modeset_mutex);
-		drm_client_for_each_modeset(mode_set, &helper->client) {
-			if (!mode_set->crtc->enabled)
-				continue;
-
-			funcs =	mode_set->crtc->helper_private;
-			if (funcs->mode_set_base_atomic == NULL)
-				continue;
-
-			if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
-				continue;
-
-			funcs->mode_set_base_atomic(mode_set->crtc,
-						    mode_set->fb,
-						    mode_set->x,
-						    mode_set->y,
-						    ENTER_ATOMIC_MODE_SET);
-		}
-		mutex_unlock(&helper->client.modeset_mutex);
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(drm_fb_helper_debug_enter);
-
-/**
- * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
- * @info: fbdev registered by the helper
- */
-int drm_fb_helper_debug_leave(struct fb_info *info)
-{
-	struct drm_fb_helper *helper = info->par;
-	struct drm_client_dev *client = &helper->client;
-	struct drm_device *dev = helper->dev;
-	struct drm_crtc *crtc;
-	const struct drm_crtc_helper_funcs *funcs;
-	struct drm_mode_set *mode_set;
-	struct drm_framebuffer *fb;
-
-	mutex_lock(&client->modeset_mutex);
-	drm_client_for_each_modeset(mode_set, client) {
-		crtc = mode_set->crtc;
-		if (drm_drv_uses_atomic_modeset(crtc->dev))
-			continue;
-
-		funcs = crtc->helper_private;
-		fb = crtc->primary->fb;
-
-		if (!crtc->enabled)
-			continue;
-
-		if (!fb) {
-			drm_err(dev, "no fb to restore?\n");
-			continue;
-		}
-
-		if (funcs->mode_set_base_atomic == NULL)
-			continue;
-
-		drm_fb_helper_restore_lut_atomic(mode_set->crtc);
-		funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
-					    crtc->y, LEAVE_ATOMIC_MODE_SET);
-	}
-	mutex_unlock(&client->modeset_mutex);
-
-	return 0;
-}
-EXPORT_SYMBOL(drm_fb_helper_debug_leave);
-
 static int
 __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
 					    bool force)
@@ -399,7 +301,6 @@ void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 	if (!preferred_bpp)
 		preferred_bpp = 32;
 
-	INIT_LIST_HEAD(&helper->kernel_fb_list);
 	spin_lock_init(&helper->damage_lock);
 	INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 	INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
@@ -541,11 +442,6 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 
 	drm_fb_helper_release_info(fb_helper);
 
-	mutex_lock(&kernel_fb_helper_lock);
-	if (!list_empty(&fb_helper->kernel_fb_list))
-		list_del(&fb_helper->kernel_fb_list);
-	mutex_unlock(&kernel_fb_helper_lock);
-
 	if (!fb_helper->client.funcs)
 		drm_client_release(&fb_helper->client);
 }
@@ -1780,10 +1676,6 @@ __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper)
 	drm_info(dev, "fb%d: %s frame buffer device\n",
 		 info->node, info->fix.id);
 
-	mutex_lock(&kernel_fb_helper_lock);
-	list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
-	mutex_unlock(&kernel_fb_helper_lock);
-
 	return 0;
 
 err_drm_fb_helper_release_info:
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index dd9a18f8de5a..05cca77b7249 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -167,13 +167,6 @@ struct drm_fb_helper {
 	struct mutex lock;
 
 	/**
-	 * @kernel_fb_list:
-	 *
-	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
-	 */
-	struct list_head kernel_fb_list;
-
-	/**
 	 * @delayed_hotplug:
 	 *
 	 * A hotplug was received while fbdev wasn't in control of the DRM
@@ -236,8 +229,6 @@ drm_fb_helper_from_client(struct drm_client_dev *client)
 	.fb_setcmap	= drm_fb_helper_setcmap, \
 	.fb_blank	= drm_fb_helper_blank, \
 	.fb_pan_display	= drm_fb_helper_pan_display, \
-	.fb_debug_enter = drm_fb_helper_debug_enter, \
-	.fb_debug_leave = drm_fb_helper_debug_leave, \
 	.fb_ioctl	= drm_fb_helper_ioctl
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
@@ -280,8 +271,6 @@ int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
 
 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
-int drm_fb_helper_debug_enter(struct fb_info *info);
-int drm_fb_helper_debug_leave(struct fb_info *info);
 #else
 static inline void drm_fb_helper_prepare(struct drm_device *dev,
 					 struct drm_fb_helper *helper,
@@ -387,16 +376,6 @@ static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
 {
 	return 0;
 }
-
-static inline int drm_fb_helper_debug_enter(struct fb_info *info)
-{
-	return 0;
-}
-
-static inline int drm_fb_helper_debug_leave(struct fb_info *info)
-{
-	return 0;
-}
 #endif
 
 #endif
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
index fe32854b7ffe..3e68213958dd 100644
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@@ -52,11 +52,6 @@ struct drm_scanout_buffer;
 struct drm_writeback_connector;
 struct drm_writeback_job;
 
-enum mode_set_atomic {
-	LEAVE_ATOMIC_MODE_SET,
-	ENTER_ATOMIC_MODE_SET,
-};
-
 /**
  * struct drm_crtc_helper_funcs - helper operations for CRTCs
  *
@@ -254,24 +249,6 @@ struct drm_crtc_helper_funcs {
 			     struct drm_framebuffer *old_fb);
 
 	/**
-	 * @mode_set_base_atomic:
-	 *
-	 * This callback is used by the fbdev helpers to set a new framebuffer
-	 * and scanout without sleeping, i.e. from an atomic calling context. It
-	 * is only used to implement kgdb support.
-	 *
-	 * This callback is optional and only needed for kgdb support in the fbdev
-	 * helpers.
-	 *
-	 * RETURNS:
-	 *
-	 * 0 on success or a negative error code on failure.
-	 */
-	int (*mode_set_base_atomic)(struct drm_crtc *crtc,
-				    struct drm_framebuffer *fb, int x, int y,
-				    enum mode_set_atomic);
-
-	/**
 	 * @disable:
 	 *
 	 * This callback should be used to disable the CRTC. With the atomic