Kernel 4.19.x does not work on BeagleBone Green Gateway

[JoseGoncalves]

Starting with the image bone-debian-10.5-console-armhf-2020-08-31-1gb.img.xz on a BeagleBone Green Gateway, I've upgraded the kernel via:

sudo apt install linux-image-4.19.135-bone55

and then rebooted.

The board boots, and I'm able to login via SSH, but shortly after it's unresponsive and the LEDs are freezed.
On the serial console, I see these messages:

[   34.183608] Bluetooth: hci0: command 0x1001 tx timeout
[   42.215635] Bluetooth: hci0: Reading TI version information failed (-110)
[   42.222621] Bluetooth: hci0: download firmware failed, retrying...
[   44.263609] Bluetooth: hci0: command 0x1001 tx timeout
[   52.455536] Bluetooth: hci0: Reading TI version information failed (-110)
[   52.462403] Bluetooth: hci0: download firmware failed, retrying...

[RobertCNelson]

I've been comparing the two device tree's, nothing really stand's out. (they are the same..)

I'll keep looking..

[JoseGoncalves]

Just to add that the same kernel upgrade procedure in a BeagleBone Green Wireless works fine.

[JoseGoncalves]

This issue is somehow related with Bluetooth in the BBGG.
If i blacklist the BT modules, adding a file /etc/modprobe.d/bluetooth-blacklist.conf:

blacklist bnep
blacklist hci_uart
blacklist bluetooth

it works!

It seems also that it's related with some race condition, because, sometimes, I've seen the 4.19.135-bone55 kernel to work with BT enabled.

[JoseGoncalves]

Some additional info dumped on the BB serial console when it crashes:

[   34.280144] Bluetooth: hci0: command 0x1001 tx timeout
[   42.472149] Bluetooth: hci0: Reading TI version information failed (-110)
[   42.479195] Bluetooth: hci0: download firmware failed, retrying...
[   44.520523] Bluetooth: hci0: command 0x1001 tx timeout
[   52.712150] Bluetooth: hci0: Reading TI version information failed (-110)
[   52.719043] Bluetooth: hci0: download firmware failed, retrying...
[   73.716018] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[   73.722155] rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-0): P2616 P875
[   73.729061] rcu: 	(detected by 0, t=5252 jiffies, g=32433, q=12)
[   73.735762] rcu: rcu_preempt kthread starved for 5248 jiffies! g32433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
[   73.746240] rcu: RCU grace-period kthread stack dump:
[  136.736014] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  136.742141] rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-0): P2616 P875
[  136.749044] rcu: 	(detected by 0, t=21007 jiffies, g=32433, q=12)
[  136.755758] rcu: rcu_preempt kthread starved for 21003 jiffies! g32433 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
[  136.766147] rcu: RCU grace-period kthread stack dump:
[  199.756011] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  199.762137] rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-0): P2616 P875
[  199.769040] rcu: 	(detected by 0, t=36762 jiffies, g=32433, q=12)
[  199.775745] rcu: rcu_preempt kthread starved for 36758 jiffies! g32433 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
[  199.786134] rcu: RCU grace-period kthread stack dump:

[JoseGoncalves]

@RobertCNelson Any progresses on this issue?
This was not very relevant to me because I did not have any issues with 4.19.x kernels from ti-linux-kernel-dev, which I am currently using in my application.
Nevertheless, recently I've seen it also happen with ti-linux-kernel-dev, what causes Bluetooth to be unavailable in BBGG.
Has I indicated previously, It seems some kind of a race condition, because in some reboots the BBGG can boot with Bluetooth enabled.