From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 From: Pintu Agarwal Date: Fri, 18 Jan 2019 15:38:48 +0530 Message-ID: Subject: Need help: how to locate failure from irq_chip subsystem Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org To: open list , linux-arm-kernel@lists.infradead.org, Russell King - ARM Linux , linux-mm@kvack.org, linux-pm@vger.kernel.org, kernelnewbies@kernelnewbies.org, Pintu Kumar List-ID: 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] [] __ipipe_dispatch_irq+0x78/0x340 [ 7.253469] [] __ipipe_grab_irq+0x5c/0xd0 [ 7.341538] [] 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