Need help: how to locate failure from irq_chip subsystem

Pintu Agarwal pintu.ping at gmail.com
Fri Jan 18 05:08:48 EST 2019


Hi All,

Currently, I am trying to debug a boot up crash on some qualcomm
snapdragon arm64 board with kernel 4.9.
I could find the cause of the failure, but I am unable to locate from
which subsystem/drivers this is getting triggered.
If you have any ideas or suggestions to locate the issue, please let me know.

This is the snapshot of crash logs:
[    6.907065] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[    6.973938] PC is at 0x0
[    6.976503] LR is at __ipipe_ack_fasteoi_irq+0x28/0x38
[    7.151078] Process qmp_aop (pid: 24, stack limit = 0xfffffffbedc18000)
[    7.242668] [<          (null)>]           (null)
[    7.247416] [<ffffff9469f8d2e0>] __ipipe_dispatch_irq+0x78/0x340
[    7.253469] [<ffffff9469e81564>] __ipipe_grab_irq+0x5c/0xd0
[    7.341538] [<ffffff9469e81d68>] gic_handle_irq+0xc0/0x154

[    6.288581] [PINTU]: __ipipe_ack_fasteoi_irq - called
[    6.293698] [PINTU]: __ipipe_ack_fasteoi_irq:
desc->irq_data.chip->irq_hold is NULL

When I check, I found that the irq_hold implementation is missing in
one of the irq_chip driver (expected by ipipe), which I am supposed to
implement.

But I am unable to locate which irq_chip driver.
If there are any good techniques to locate this in kernel, please help.


Thanks,
Pintu



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