We have several SBC Nanopi R5C. This beautiful little device works fine with the manufacturer OS, but due to a very strange configuration of this OS (Debian based, but installed on seven partitions), it is impossible to compile with this OS. Since we need to compile our own module, we switched to a pure Debian 12, using the Dietpi distribution. Here we have a very strange behaviour.
On cold boots, the WiFi is not visible in lspci, and wlan0 is not present. When we reboot, all is fine, the WiFi card is visible in lspci and the WiFi works normally. The error message in the boot log, after a cold boot is :

DietPi kernel: [    1.034752] pci_bus 0000:01: busn_res: can not insert [bus 01-ff] under [bus 00-0f] (conflicts with (null) [bus 00-0f])

It is strange that after a reboot all is fine. We have tried a dirty workaround with an automatic reboot after a cold boot, but this is obviously not a solution.
We tried to rescan the pci bus. Then the card is visible in lspci, but wlan0 is still not present and no way was found to make it appear.
Is there a way to create some delay before the pci bus is scanned ?