[PATCH v2] drm/msm: properly add and remove internal bridges

[Stephen Boyd]

Quoting Dmitry Baryshkov (2022-04-11 16:49:53)
> Add calls to drm_bridge_add()/drm_bridge_remove() DRM bridges created by
> the driver. This fixes the following warning.
>
> WARNING: CPU: 0 PID: 1 at kernel/locking/mutex.c:579 __mutex_lock+0x840/0x9f4
> DEBUG_LOCKS_WARN_ON(lock->magic != lock)
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc1-00002-g3054695a0d27-dirty #55
> Hardware name: Generic DT based system
>  unwind_backtrace from show_stack+0x10/0x14
>  show_stack from dump_stack_lvl+0x58/0x70
>  dump_stack_lvl from __warn+0xc8/0x1e8
>  __warn from warn_slowpath_fmt+0x78/0xa8
>  warn_slowpath_fmt from __mutex_lock+0x840/0x9f4
>  __mutex_lock from mutex_lock_nested+0x1c/0x24
>  mutex_lock_nested from drm_bridge_hpd_enable+0x2c/0x84
>  drm_bridge_hpd_enable from msm_hdmi_modeset_init+0xc0/0x21c
>  msm_hdmi_modeset_init from mdp4_kms_init+0x53c/0x90c
>  mdp4_kms_init from msm_drm_bind+0x514/0x698
>  msm_drm_bind from try_to_bring_up_aggregate_device+0x160/0x1bc
>  try_to_bring_up_aggregate_device from component_master_add_with_match+0xc4/0xf8
>  component_master_add_with_match from msm_pdev_probe+0x274/0x350
>  msm_pdev_probe from platform_probe+0x5c/0xbc
>  platform_probe from really_probe.part.0+0x9c/0x290
>  really_probe.part.0 from __driver_probe_device+0xa8/0x13c
>  __driver_probe_device from driver_probe_device+0x34/0x10c
>  driver_probe_device from __driver_attach+0xbc/0x178
>  __driver_attach from bus_for_each_dev+0x74/0xc0
>  bus_for_each_dev from bus_add_driver+0x160/0x1e4
>  bus_add_driver from driver_register+0x88/0x118
>  driver_register from do_one_initcall+0x6c/0x334
>  do_one_initcall from kernel_init_freeable+0x1bc/0x220
>  kernel_init_freeable from kernel_init+0x18/0x12c
>  kernel_init from ret_from_fork+0x14/0x2c
>
> Fixes: 3d3f8b1f8b62 ("drm/bridge: make bridge registration independent of drm flow")
> Reported-by: kernel test robot <lkp at intel.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---

Reviewed-by: Stephen Boyd <swboyd at chromium.org>