On 12/01/2023 11:35, Neil Armstrong wrote:
On 11/01/2023 13:41, Marek Szyprowski wrote:
On 02.11.2022 19:07, Dmitry Baryshkov wrote:
Use drm_connector's helpers enable_hpd and disable_hpd to enable and
disable HPD automatically by the means of drm_kms_helper_poll_*
functions. As the drm_bridge_connector_enable_hpd() and
drm_bridge_connector_disable_hpd() functions are now unused, replace
them with stubs to ease driver migration.
Enabling the HPD from drm_bridge_connector_init() can happen too early,
before the driver is prepared to handle HPD events. As the
drm_bridge_connector_enable_hpd() is empty anyway, drop this call
anyway.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
This patch, merged to recent linux-next as commit 92d755d8f13b
("drm/bridge_connector: rely on drm_kms_helper_poll_* for HPD
enablement"), triggers the following warning on all my Amlogic Meson
based boards:
------------[ cut here ]------------
Hot plug detection already enabled
WARNING: CPU: 2 PID: 285 at drivers/gpu/drm/drm_bridge.c:1257
drm_bridge_hpd_enable+0x90/0xa0
Modules linked in: snd_soc_meson_axg_frddr snd_soc_meson_axg_fifo
dwmac_generic panfrost(+) reset_meson_audio_arb(+) drm_shmem_helper
meson_dw_hdmi(+) dw_hdmi rc_odroid drm_display_helper meson_ir(+)
gpu_sched meson_rng rng_core meson_gxbb_wdt crct10dif_ce dwmac_meson8b
stmmac_platform snd_soc_meson_axg_sound_card snd_soc_meson_card_utils
mdio_mux_meson_g12a stmmac meson_drm pwm_meson pcs_xpcs meson_canvas
snd_soc_meson_axg_tdm_interface rtc_meson_vrtc
snd_soc_meson_axg_tdm_formatter nvmem_meson_efuse display_connector
CPU: 2 PID: 285 Comm: systemd-udevd Not tainted 6.1.0-rc6+ #13236
Hardware name: Hardkernel ODROID-C4 (DT)
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drm_bridge_hpd_enable+0x90/0xa0
lr : drm_bridge_hpd_enable+0x90/0xa0
...
Call trace:
drm_bridge_hpd_enable+0x90/0xa0
_drm_bridge_connector_enable_hpd+0x24/0x34
Weird because _drm_bridge_connector_enable_hpd() has been removed with
4c00ac500d0e ("drm/bridge_connector: drop
drm_bridge_connector_en/disable_hpd()")
drm_kms_helper_poll_enable.part.0+0x50/0xd0
It seems drm_kms_helper_poll_enable is called again by
drm_helper_probe_single_connector_modes() because poll_running isn't set.
Yes, I'm currently reworking poll_running handling. I hope to post a
patch today.
--
With best wishes
Dmitry
