Re: [PATCH] drm/connector: Cache out-of-band hotplug events

[Igor Paunovic <royalnet026@gmail.com>]

Hi Sebastian,

On 8/21/26 16:55, Sebastian Reichel wrote:
> When the USB-C state machine finished negotiating DP AltMode before the
> DRM device has been probed, the out-of-band hotplug events fired to
> early and are lost. Without replugging the display or reloading the
> USB-C driver, the DRM driver assumes nothing is plugged.

This is the boot race I reported in [1], and the patch fixes it here.

Orange Pi 5 Plus (RK3588), a Samsung monitor on USB-C DisplayPort Alt
Mode behind fusb302, on drm-misc-next plus the dw-dp and Rockchip USBDP
PHY series.  The same tree also carries my pending vop2 AXI clock patch
and the pending dw-hdmi-qp audio guard; without those two the board
does not survive the boot for reasons unrelated to this patch.

Without the patch (one boot on that tree, two more on my daily kernel)
the DP connector reads "disconnected" from the moment dw-dp binds until
a boot-time service of mine unbinds and rebinds fusb302 some 45-70 s
later; only then does the link come up.

With the patch the display comes up on its own: the same service,
running 40 s after dw-dp bound, finds the connector already "connected"
and does nothing.  No warnings over the session.

Tested-by: Igor Paunovic <royalnet026@gmail.com> # Orange Pi 5 Plus, USB-C DP Alt Mode

[1] https://lore.kernel.org/all/20260811211534.8618-1-royalnet026@gmail.com/

Thanks,
Igor