drm/msm: VT console DisplayPort regression in 6.8-rc1

drm/msm: VT console DisplayPort regression in 6.8-rc1

[Johan Hovold]

Hi,

Since 6.8-rc1 the VT console is no longer mirrored on an external
display on coldplug or hotplug on the Lenovo ThinkPad X13s.

The hotplug notification appears to be generated immediately but it is
no longer forwarded or processed correctly:

[   22.578434] msm_dpu ae01000.display-controller: msm_fbdev_client_hotplug
[   22.953161] msm_dpu ae01000.display-controller: msm_fbdev_client_hotplug
[   23.095122] msm_dpu ae01000.display-controller: msm_fbdev_client_hotplug
[   24.185683] msm_dpu ae01000.display-controller: msm_fbdev_client_hotplug
[   24.186197] msm-dp-display ae98000.displayport-controller: dp_pm_runtime_resume
[   24.188098] msm-dp-display ae98000.displayport-controller: dp_ctrl_phy_init
[   24.191805] msm_dpu ae01000.display-controller: msm_fbdev_client_hotplug
[   24.275904] [drm-dp] dp_ctrl_on_link: dp_ctrl_on_link - drm_dev = 0000000000000000
[   24.276474] [drm-dp] dp_ctrl_enable_mainlink_clocks: dp_ctrl_enable_mainlink_clocks - drm_dev = 0000000000000000

as the external display remains off/blank.

I've verified that reverting commit e467e0bde881 ("drm/msm/dp: use
drm_bridge_hpd_notify() to report HPD status changes") fixes "both"
issues.

I've previously reported this here:

	https://gitlab.freedesktop.org/drm/msm/-/issues/50

Note that a couple of times the display was eventually mirrored after a
very long timeout, but this doesn't seem to always be the case.

Johan


#regzbot introduced: e467e0bde881

Re: drm/msm: VT console DisplayPort regression in 6.8-rc1

[Linux regression tracking #update (Thorsten Leemhuis)]

[send with a reduced set of recipients, we all get enough mail already]

On 27.02.24 13:40, Johan Hovold wrote:
> 
> Since 6.8-rc1 the VT console is no longer mirrored on an external
> display on coldplug or hotplug on the Lenovo ThinkPad X13s.
>

Thx for the report!

> I've previously reported this here:
> 
> 	https://gitlab.freedesktop.org/drm/msm/-/issues/50

Then let's tell regzbot about is as well, in case the ticket comes back
to life now:

#regzbot duplicate: https://gitlab.freedesktop.org/drm/msm/-/issues/50

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
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