Revert "drm: add a locked version of drm_is_current_master"

commit f54b3ca7ea1e5e02f481cf4ca54568e57bd66086 upstream.

This reverts commit 1815d9c86e3090477fbde066ff314a7e9721ee0f.

Unfortunately this inverts the locking hierarchy, so back to the
drawing board. Full lockdep splat below:

======================================================
WARNING: possible circular locking dependency detected
5.13.0-rc7-CI-CI_DRM_10254+ #1 Not tainted
------------------------------------------------------
kms_frontbuffer/1087 is trying to acquire lock:
ffff88810dcd01a8 (&dev->master_mutex){+.+.}-{3:3}, at: drm_is_current_master+0x1b/0x40
but task is already holding lock:
ffff88810dcd0488 (&dev->mode_config.mutex){+.+.}-{3:3}, at: drm_mode_getconnector+0x1c6/0x4a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&dev->mode_config.mutex){+.+.}-{3:3}:
       __mutex_lock+0xab/0x970
       drm_client_modeset_probe+0x22e/0xca0
       __drm_fb_helper_initial_config_and_unlock+0x42/0x540
       intel_fbdev_initial_config+0xf/0x20 [i915]
       async_run_entry_fn+0x28/0x130
       process_one_work+0x26d/0x5c0
       worker_thread+0x37/0x380
       kthread+0x144/0x170
       ret_from_fork+0x1f/0x30
-> #1 (&client->modeset_mutex){+.+.}-{3:3}:
       __mutex_lock+0xab/0x970
       drm_client_modeset_commit_locked+0x1c/0x180
       drm_client_modeset_commit+0x1c/0x40
       __drm_fb_helper_restore_fbdev_mode_unlocked+0x88/0xb0
       drm_fb_helper_set_par+0x34/0x40
       intel_fbdev_set_par+0x11/0x40 [i915]
       fbcon_init+0x270/0x4f0
       visual_init+0xc6/0x130
       do_bind_con_driver+0x1e5/0x2d0
       do_take_over_console+0x10e/0x180
       do_fbcon_takeover+0x53/0xb0
       register_framebuffer+0x22d/0x310
       __drm_fb_helper_initial_config_and_unlock+0x36c/0x540
       intel_fbdev_initial_config+0xf/0x20 [i915]
       async_run_entry_fn+0x28/0x130
       process_one_work+0x26d/0x5c0
       worker_thread+0x37/0x380
       kthread+0x144/0x170
       ret_from_fork+0x1f/0x30
-> #0 (&dev->master_mutex){+.+.}-{3:3}:
       __lock_acquire+0x151e/0x2590
       lock_acquire+0xd1/0x3d0
       __mutex_lock+0xab/0x970
       drm_is_current_master+0x1b/0x40
       drm_mode_getconnector+0x37e/0x4a0
       drm_ioctl_kernel+0xa8/0xf0
       drm_ioctl+0x1e8/0x390
       __x64_sys_ioctl+0x6a/0xa0
       do_syscall_64+0x39/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of: &dev->master_mutex --> &client->modeset_mutex --> &dev->mode_config.mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&dev->mode_config.mutex);
                               lock(&client->modeset_mutex);
                               lock(&dev->mode_config.mutex);
  lock(&dev->master_mutex);

0 files changed, 0 insertions, 0 deletions