Driver Timeout at boot, dual MT7915E, UniElec U7621-06 (16M flash) Openwrt

Boot from poweroff works perfect, when I reboot the system the driver seems to have a problem. If i only use one of the two modules, everything is alright.

rmmod mt7915e
modprobe 7915e
--> same error

If I unplugg 12V and put it back in, the two radios work perfect again. if i click reboot it happens again.
--> driver only works once after poweroff reset
--> softreset leads to that error

Same thing on Openwrt 20.02.1 and current snap (28.01.22)

after reboot-->

Thu Jan 27 16:47:10 2022 user.info kernel: [ 13.779669] kmodloader: loading kernel modules from /etc/modules.d/*
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 14.089957] Loading modules backported from Linux version v5.15.8-0-g43e577d7a2cb
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 14.097482] Backport generated by backports.git v5.15.8-1-0-g83f664bb
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 14.815303] mt7621-pci 1e140000.pcie: bus=2 slot=1 irq=24
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 14.820778] pci 0000:00:01.0: enabling device (0000 -> 0003)
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 14.826504] mt7915e 0000:02:00.0: enabling device (0000 -> 0002)
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 35.183619] mt7915e 0000:02:00.0: Message 00000010 (seq 1) timeout
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 35.189802] mt7915e 0000:02:00.0: Failed to get patch semaphore
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 55.663612] mt7915e 0000:02:00.0: Message 00000010 (seq 2) timeout
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 55.669786] mt7915e 0000:02:00.0: Failed to get patch semaphore
Thu Jan 27 16:47:10 2022 kern.warn kernel: [ 55.675942] mt7915e: probe of 0000:02:00.0 failed with error -11
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 55.682031] mt7621-pci 1e140000.pcie: bus=3 slot=2 irq=25
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 55.687480] pci 0000:00:02.0: enabling device (0000 -> 0003)
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 55.693125] mt7915e 0000:03:00.0: enabling device (0000 -> 0002)
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 76.143606] mt7915e 0000:03:00.0: Message 00000010 (seq 1) timeout
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 76.149787] mt7915e 0000:03:00.0: Failed to get patch semaphore
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 96.623585] mt7915e 0000:03:00.0: Message 00000010 (seq 2) timeout
Thu Jan 27 16:47:10 2022 kern.err kernel: [ 96.629743] mt7915e 0000:03:00.0: Failed to get patch semaphore
Thu Jan 27 16:47:10 2022 kern.warn kernel: [ 96.635884] mt7915e: probe of 0000:03:00.0 failed with error -11
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 96.699024] PPP generic driver version 2.4.2
Thu Jan 27 16:47:10 2022 kern.info kernel: [ 96.705681] NET: Registered protocol family 24
Thu Jan 27 16:47:10 2022 user.info kernel: [ 96.718951] kmodloader: done loading kernel modules from /etc/modules.d/*

Clean poweroff boot-->

Thu Jan 27 16:45:50 2022 user.info kernel: [ 13.775271] kmodloader: loading kernel modules from /etc/modules.d/*
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.062810] Loading modules backported from Linux version v5.15.8-0-g43e577d7a2cb
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.070290] Backport generated by backports.git v5.15.8-1-0-g83f664bb
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.783773] mt7621-pci 1e140000.pcie: bus=2 slot=1 irq=24
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.789247] pci 0000:00:01.0: enabling device (0004 -> 0007)
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.794979] mt7915e 0000:02:00.0: enabling device (0000 -> 0002)
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.951811] mt7915e 0000:02:00.0: HW/SW Version: 0x8a108a10, Build Time: 20201105222230a
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 14.951811]
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 15.720032] mt7915e 0000:02:00.0: WM Firmware Version: ____000000, Build Time: 20201105222304
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 15.893002] mt7915e 0000:02:00.0: WA Firmware Version: DEV_000000, Build Time: 20201105222323
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.055388] mt7621-pci 1e140000.pcie: bus=3 slot=2 irq=25
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.060909] pci 0000:00:02.0: enabling device (0004 -> 0007)
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.066691] mt7915e 0000:03:00.0: enabling device (0000 -> 0002)
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.093706] mt7915e 0000:03:00.0: HW/SW Version: 0x8a108a10, Build Time: 20201105222230a
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.093706]
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.122920] mt7915e 0000:03:00.0: WM Firmware Version: ____000000, Build Time: 20201105222304
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.162588] mt7915e 0000:03:00.0: WA Firmware Version: DEV_000000, Build Time: 20201105222323
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.382587] PPP generic driver version 2.4.2
Thu Jan 27 16:45:50 2022 kern.info kernel: [ 16.389072] NET: Registered protocol family 24
Thu Jan 27 16:45:50 2022 user.info kernel: [ 16.403858] kmodloader: done loading kernel modules from /etc/modules.d/*

Start with the mt7915e PCI probe path and the firmware initialization messages shown in the reboot logs, especially the patch semaphore timeout. Compare the soft-reboot and poweroff boot sequences for both PCI devices. Done means both MT7915E modules initialize successfully after a soft reboot as well as after poweroff.