drm/client: Pass force parameter to client restore

Add force parameter to client restore and pass value through the
layers. The only currently used value is false.

If force is true, the client should restore its display even if it
does not hold the DRM master lock. This is be required for emergency
output, such as sysrq.

While at it, inline drm_fb_helper_lastclose(), which is a trivial
wrapper around drm_fb_helper_restore_fbdev_mode_unlocked().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20251110154616.539328-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
index 47e5f27eee58724959fec3b38bda338189f54880..28951e39248258f9637469477666a481b1d309db 100644 (file)
--- a/drivers/gpu/drm/clients/drm_fbdev_client.c
+++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
@@ -38,9 +38,11 @@ static void drm_fbdev_client_unregister(struct drm_client_dev *client)
        }
 }
 
-static int drm_fbdev_client_restore(struct drm_client_dev *client)
+static int drm_fbdev_client_restore(struct drm_client_dev *client, bool force)
 {
-       drm_fb_helper_lastclose(client->dev);
+       struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+       drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
 
        return 0;
 }

diff --git a/drivers/gpu/drm/drm_client_event.c b/drivers/gpu/drm/drm_client_event.c
index d25dc5250983ad9ebf1c3218985f7fdb233229c1..7b3e362f7926cf6ebb307c2ee23985759c62ab1f 100644 (file)
--- a/drivers/gpu/drm/drm_client_event.c
+++ b/drivers/gpu/drm/drm_client_event.c
@@ -102,7 +102,7 @@ void drm_client_dev_hotplug(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_client_dev_hotplug);
 
-void drm_client_dev_restore(struct drm_device *dev)
+void drm_client_dev_restore(struct drm_device *dev, bool force)
 {
        struct drm_client_dev *client;
        int ret;
@@ -115,7 +115,7 @@ void drm_client_dev_restore(struct drm_device *dev)
                if (!client->funcs || !client->funcs->restore)
                        continue;
 
-               ret = client->funcs->restore(client);
+               ret = client->funcs->restore(client, force);
                drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
                if (!ret) /* The first one to return zero gets the privilege to restore */
                        break;

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 53e9dc0543de856452d96b376097461c8f26bf16..1392738ce2fed8682270260c42f2a1bef7d6c73c 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -255,6 +255,7 @@ __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
 /**
  * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
  * @fb_helper: driver-allocated fbdev helper, can be NULL
+ * @force: ignore present DRM master
  *
  * This helper should be called from fbdev emulation's &drm_client_funcs.restore
  * callback. It ensures that the user isn't greeted with a black screen when the
@@ -263,9 +264,9 @@ __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
  * Returns:
  * 0 on success, or a negative errno code otherwise.
  */
-int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
+int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper, bool force)
 {
-       return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
+       return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
 }
 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 
@@ -1328,9 +1329,9 @@ int drm_fb_helper_set_par(struct fb_info *info)
         * the KDSET IOCTL with KD_TEXT, and only after that drops the master
         * status when exiting.
         *
-        * In the past this was caught by drm_fb_helper_lastclose(), but on
-        * modern systems where logind always keeps a drm fd open to orchestrate
-        * the vt switching, this doesn't work.
+        * In the past this was caught by drm_fb_helper_restore_fbdev_mode_unlocked(),
+        * but on modern systems where logind always keeps a drm fd open to
+        * orchestrate the vt switching, this doesn't work.
         *
         * To not break the userspace ABI we have this special case here, which
         * is only used for the above case. Everything else uses the normal
@@ -1955,16 +1956,3 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
        return 0;
 }
 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
-
-/**
- * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
- * @dev: DRM device
- *
- * This function is obsolete. Call drm_fb_helper_restore_fbdev_mode_unlocked()
- * instead.
- */
-void drm_fb_helper_lastclose(struct drm_device *dev)
-{
-       drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
-}
-EXPORT_SYMBOL(drm_fb_helper_lastclose);

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index eebd1a05ee97444b0e459032e71bc2ef31afdaa8..be5e617ceb9f13d187475593b702155b86a76881 100644 (file)
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -405,7 +405,7 @@ EXPORT_SYMBOL(drm_open);
 
 static void drm_lastclose(struct drm_device *dev)
 {
-       drm_client_dev_restore(dev);
+       drm_client_dev_restore(dev, false);
 
        if (dev_is_pci(dev->dev))
                vga_switcheroo_process_delayed_switch();

diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 5ecde0f6f59135877a249fd62463c881e3a26904..c972a8a3385b3b9ef8c316a24562b20f1c7f6af4 100644 (file)
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -57,12 +57,14 @@ struct drm_client_funcs {
         *
         * Note that the core does not guarantee exclusion against concurrent
         * drm_open(). Clients need to ensure this themselves, for example by
-        * using drm_master_internal_acquire() and
-        * drm_master_internal_release().
+        * using drm_master_internal_acquire() and drm_master_internal_release().
+        *
+        * If the caller passes force, the client should ignore any present DRM
+        * master and restore the display anyway.
         *
         * This callback is optional.
         */
-       int (*restore)(struct drm_client_dev *client);
+       int (*restore)(struct drm_client_dev *client, bool force);
 
        /**
         * @hotplug:

diff --git a/include/drm/drm_client_event.h b/include/drm/drm_client_event.h
index 985d6f02a4c432e3c6fbbaf7a9f5d0b92998b09b..79369c755bc90dd8efd9ae68d24c16caa7864b03 100644 (file)
--- a/include/drm/drm_client_event.h
+++ b/include/drm/drm_client_event.h
@@ -10,7 +10,7 @@ struct drm_device;
 #if defined(CONFIG_DRM_CLIENT)
 void drm_client_dev_unregister(struct drm_device *dev);
 void drm_client_dev_hotplug(struct drm_device *dev);
-void drm_client_dev_restore(struct drm_device *dev);
+void drm_client_dev_restore(struct drm_device *dev, bool force);
 void drm_client_dev_suspend(struct drm_device *dev);
 void drm_client_dev_resume(struct drm_device *dev);
 #else
@@ -18,7 +18,7 @@ static inline void drm_client_dev_unregister(struct drm_device *dev)
 { }
 static inline void drm_client_dev_hotplug(struct drm_device *dev)
 { }
-static inline void drm_client_dev_restore(struct drm_device *dev)
+static inline void drm_client_dev_restore(struct drm_device *dev, bool force)
 { }
 static inline void drm_client_dev_suspend(struct drm_device *dev)
 { }

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index c1d38d54a11204fe9fe3795f1f6b382dd7aa5a93..63e3af8dd5ed1b1f9eccb60c18eb3fe2936f7158 100644 (file)
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -254,7 +254,8 @@ int drm_fb_helper_set_par(struct fb_info *info);
 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
                            struct fb_info *info);
 
-int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
+int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
+                                             bool force);
 
 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper);
 void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper);
@@ -283,7 +284,6 @@ 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);
-void drm_fb_helper_lastclose(struct drm_device *dev);
 #else
 static inline void drm_fb_helper_prepare(struct drm_device *dev,
                                         struct drm_fb_helper *helper,
@@ -409,10 +409,6 @@ static inline int drm_fb_helper_debug_leave(struct fb_info *info)
 {
        return 0;
 }
-
-static inline void drm_fb_helper_lastclose(struct drm_device *dev)
-{
-}
 #endif
 
 #endif