[PATCH] drm/vc4: crtc: Fix runtime_pm reference counting

[Stefan Wahren]

Hi Maxime,

i applied your patch on top of Linux 5.17-rc4 and it fixes the tones of
warnings after boot (see below). So you can have my

Tested-by: Stefan Wahren <stefan.wahren at i2se.com>

[    8.341814] ------------[ cut here ]------------
[    8.341820] WARNING: CPU: 1 PID: 7 at
drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417
vc4_hdmi_write_infoframe+0x494/0x69c [vc4]
[    8.341861] Modules linked in: snd_soc_hdmi_codec brcmfmac
sha256_generic libsha256 sha256_arm cfg80211 brcmutil hci_uart btbcm
bluetooth vc4 ecdh_generic ecc libaes raspberrypi_hwmon snd_soc_core
ac97_bus snd_pcm_dmaengine snd_pcm snd_timer bcm2711_thermal
crc32_arm_ce snd genet soundcore drm_cma_helper mdio_bcm_unimac nvmem_rmem
[    8.341925] CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.17.0-rc4 #21
[    8.341930] Hardware name: BCM2711
[    8.341933] Workqueue: events_unbound deferred_probe_work_func
[    8.341953]  unwind_backtrace from show_stack+0x10/0x14
[    8.341964]  show_stack from dump_stack_lvl+0x40/0x4c
[    8.341974]  dump_stack_lvl from __warn+0x14c/0x150
[    8.341983]  __warn from warn_slowpath_fmt+0xac/0xb4
[    8.341989]  warn_slowpath_fmt from
vc4_hdmi_write_infoframe+0x494/0x69c [vc4]
[    8.342026]  vc4_hdmi_write_infoframe [vc4] from
vc4_hdmi_encoder_post_crtc_enable+0x13ec/0x1910 [vc4]
[    8.342072]  vc4_hdmi_encoder_post_crtc_enable [vc4] from
drm_atomic_helper_commit_modeset_enables+0xa8/0x290
[    8.342104]  drm_atomic_helper_commit_modeset_enables from
vc4_atomic_commit_tail+0x230/0x700 [vc4]
[    8.342137]  vc4_atomic_commit_tail [vc4] from commit_tail+0xa4/0x194
[    8.342169]  commit_tail from drm_atomic_helper_commit+0x134/0x158
[    8.342178]  drm_atomic_helper_commit from
drm_client_modeset_commit_atomic+0x208/0x230
[    8.342192]  drm_client_modeset_commit_atomic from
drm_client_modeset_commit_locked+0x44/0x188
[    8.342206]  drm_client_modeset_commit_locked from
drm_client_modeset_commit+0x24/0x40
[    8.342214]  drm_client_modeset_commit from
__drm_fb_helper_restore_fbdev_mode_unlocked+0x60/0xc4
[    8.342225]  __drm_fb_helper_restore_fbdev_mode_unlocked from
drm_fb_helper_set_par+0x38/0x64
[    8.342233]  drm_fb_helper_set_par from fbcon_init+0x2f8/0x49c
[    8.342243]  fbcon_init from visual_init+0xbc/0x104
[    8.342253]  visual_init from do_bind_con_driver+0x1f0/0x3fc
[    8.342260]  do_bind_con_driver from do_take_over_console+0x84/0x1e0
[    8.342269]  do_take_over_console from do_fbcon_takeover+0x74/0xcc
[    8.342276]  do_fbcon_takeover from register_framebuffer+0x208/0x2dc
[    8.342285]  register_framebuffer from
__drm_fb_helper_initial_config_and_unlock+0x3f0/0x5bc
[    8.342293]  __drm_fb_helper_initial_config_and_unlock from
drm_fbdev_client_hotplug+0x118/0x1a8
[    8.342301]  drm_fbdev_client_hotplug from
drm_fbdev_generic_setup+0xa4/0x1a8
[    8.342308]  drm_fbdev_generic_setup from vc4_drm_bind+0x1b0/0x1b4 [vc4]
[    8.342336]  vc4_drm_bind [vc4] from try_to_bring_up_master+0x15c/0x1b4
[    8.342362]  try_to_bring_up_master from
component_master_add_with_match+0xc4/0xf8
[    8.342369]  component_master_add_with_match from
vc4_platform_drm_probe+0xa8/0xcc [vc4]
[    8.342396]  vc4_platform_drm_probe [vc4] from platform_probe+0x5c/0xb8
[    8.342425]  platform_probe from really_probe+0xc0/0x2fc
[    8.342430]  really_probe from __driver_probe_device+0x84/0xe4
[    8.342435]  __driver_probe_device from driver_probe_device+0x34/0xd4
[    8.342440]  driver_probe_device from __device_attach_driver+0x88/0xb4
[    8.342445]  __device_attach_driver from bus_for_each_drv+0x54/0xb4
[    8.342453]  bus_for_each_drv from __device_attach+0xdc/0x148
[    8.342460]  __device_attach from bus_probe_device+0x84/0x8c
[    8.342466]  bus_probe_device from deferred_probe_work_func+0x7c/0xa8
[    8.342475]  deferred_probe_work_func from process_one_work+0x228/0x524
[    8.342486]  process_one_work from worker_thread+0x40/0x56c
[    8.342493]  worker_thread from kthread+0xd8/0xf4
[    8.342501]  kthread from ret_from_fork+0x14/0x1c
[    8.342508] Exception stack(0xc20c3fb0 to 0xc20c3ff8)
[    8.342513] 3fa0:                                     00000000
00000000 00000000 00000000
[    8.342518] 3fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    8.342523] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    8.342527] ---[ end trace 0000000000000000 ]---

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