Troubleshooting • Kernel oops loading hifiberry-dacplus driver

Code:

[   16.263394] 8<--- cut here ---[   16.265254] Unable to handle kernel NULL pointer dereference at virtual address 00000004 when write[   16.268774] [00000004] *pgd=00000000[   16.270822] Internal error: Oops: 805 [#1] SMP ARM[   16.272750] Modules linked in: snd_soc_pcm512x_i2c snd_soc_pcm512x regmap_i2c snd_soc_hifiberry_dacplus snd_soc_bcm2835_i2s raspberrypi_ts raspberrypi_hwmon snd_soc_core snd_compress snd_pcm_dmaengine snd_bcm2835(C) snd_pcm i2c_bcm2835 raspberrypi_gpiomem rpi_backlight snd_timer backlight snd clk_hifiberry_dacpro fixed squashfs zram lz4_compress[   16.280136] CPU: 2 UID: 0 PID: 120 Comm: kworker/u19:2 Tainted: G         C         6.12.28-pcpCore-v7 #30[   16.284299] Tainted: [C]=CRAP[   16.286149] Hardware name: BCM2835[   16.287953] Workqueue: events_unbound deferred_probe_work_func[   16.289717] PC is at snd_rpi_hifiberry_dacplus_init+0x44/0x2ec [snd_soc_hifiberry_dacplus][   16.291506] LR is at snd_soc_link_init+0x28/0x6c [snd_soc_core][   16.293633] pc : [<7f1868fc>]    lr : [<7f11ea38>]    psr: 20000013[   16.295470] sp : bc179d10  ip : 00000001  fp : 00000003[   16.297151] r10: 00000000  r9 : 00000001  r8 : 7f188124[   16.298809] r7 : 7f1881a8  r6 : 81764840  r5 : 85aad840  r4 : 7f188600[   16.300461] r3 : fffffffe  r2 : 00000001  r1 : 00000001  r0 : 81764840[   16.302052] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none[   16.303636] Control: 10c5383d  Table: 0b09806a  DAC: 00000051[   16.305409] Register r0 information: slab kmalloc-2k start 81764800 pointer offset 64 size 2048[   16.307149] Register r1 information: non-paged memory[   16.308733] Register r2 information: non-paged memory[   16.310250] Register r3 information: non-paged memory[   16.311662] Register r4 information: 2-page vmalloc region starting at 0x7f188000 allocated at load_module+0x704/0x1ca4[   16.314637] Register r5 information: slab kmalloc-256 start 85aad800 pointer offset 64 size 256[   16.316172] Register r6 information: slab kmalloc-2k start 81764800 pointer offset 64 size 2048[   16.317906] Register r7 information: 2-page vmalloc region starting at 0x7f188000 allocated at load_module+0x704/0x1ca4[   16.320959] Register r8 information: 2-page vmalloc region starting at 0x7f188000 allocated at load_module+0x704/0x1ca4[   16.323833] Register r9 information: non-paged memory[   16.325300] Register r10 information: NULL pointer[   16.326789] Register r11 information: non-paged memory[   16.328455] Register r12 information: non-paged memory[   16.329950] Process kworker/u19:2 (pid: 120, stack limit = 0xb7b40fe4)[   16.331534] Stack: (0xbc179d10 to 0xbc17a000)[   16.332897] 9d00:                                     81764840 7f1880a8 81764840 7f1881a8[   16.334361] 9d20: 7f188124 00000003 7f188140 7f11ea38 81764840 7f1881a8 7f18806c 7f10c1b4[   16.335831] 9d40: 00000000 7f1880a0 40004045 7f188240 7f123000 7f188124 7f1880a8 7f18806c[   16.337279] 9d60: 85f70b80 7f1881a8 81553805 8239b340 7f188600 7f18806c 817ec410 02600000[   16.338694] 9d80: 81553805 82dc3600 81555e20 7f11d658 7f14348c 798fea52 7f188004 7f188004[   16.340424] 9da0: 7f188600 817ec400 817ec410 7f1866cc 00000000 bc179dcc 81555e20 00000000[   16.342104] 9dc0: 00000000 00000000 00000000 b6b75adc 00000000 00000000 00000000 00000000[   16.343548] 9de0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000[   16.344974] 9e00: 00000000 00000000 00000000 00000000 00000000 798fea52 7f188018 00000000[   16.346411] 9e20: 817ec410 7f188018 00000000 80820464 817ec410 00000000 7f188018 00000000[   16.347891] 9e40: 02600000 8081dc30 817ec410 7f188018 817ec410 0000002b 02600000 8081dec0[   16.349357] 9e60: 60000013 81553805 812e1800 7f188018 817ec410 0000002b 02600000 8081e0b0[   16.350618] 9e80: 00000001 7f188018 bc179edc 817ec410 02600000 8081e220 00000000 8168d300[   16.352243] 9ea0: bc179edc 8081e184 02600000 8081bddc 8168d300 8168d36c 8b0234b8 798fea52[   16.353694] 9ec0: 81555e20 817ec410 817ec454 00000001 8168d300 8081e564 00000001 817ec410[   16.355225] 9ee0: 00000001 798fea52 817ec410 817ec410 8122345c 8081ccf8 817ec410 81223448[   16.356579] 9f00: 8122345c 00000000 02600000 8081d1b0 83000200 81223480 81553800 81555e00[   16.357939] 9f20: 02600000 8013b1c0 bc179ee0 bc179f4c 8013f188 801444c4 00000013 ffffffff[   16.359263] 9f40: 83000200 81555e00 81103d40 81555e20 61c88647 8300022c 82dc3600 8013b680[   16.360519] 9f60: 83000200 81c01c80 bb8d5ec0 817e28c0 82dc3600 8013b414 83000200 81c01c80[   16.361875] 9f80: bb8d5ec0 00000000 00000000 80145924 817e28c0 8014583c 00000000 00000000[   16.363365] 9fa0: 00000000 00000000 00000000 8010012c 00000000 00000000 00000000 00000000[   16.364903] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000[   16.366385] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000[   16.367726] Call trace:[   16.367751]  snd_rpi_hifiberry_dacplus_init [snd_soc_hifiberry_dacplus] from snd_soc_link_init+0x28/0x6c [snd_soc_core][   16.371767]  snd_soc_link_init [snd_soc_core] from snd_soc_bind_card+0x628/0xcf0 [snd_soc_core][   16.373470]  snd_soc_bind_card [snd_soc_core] from devm_snd_soc_register_card+0x4c/0x8c [snd_soc_core][   16.376694]  devm_snd_soc_register_card [snd_soc_core] from snd_rpi_hifiberry_dacplus_probe+0x208/0x3f4 [snd_soc_hifiberry_dacplus][   16.379968]  snd_rpi_hifiberry_dacplus_probe [snd_soc_hifiberry_dacplus] from platform_probe+0x64/0xb8[   16.383113]  platform_probe from really_probe+0xd0/0x2d0[   16.384744]  really_probe from __driver_probe_device+0x90/0x1a8[   16.386368]  __driver_probe_device from driver_probe_device+0x38/0x10c[   16.388286]  driver_probe_device from __device_attach_driver+0x9c/0x110[   16.390078]  __device_attach_driver from bus_for_each_drv+0x98/0xec[   16.391701]  bus_for_each_drv from __device_attach+0xb0/0x1ac[   16.393337]  __device_attach from bus_probe_device+0x90/0x94[   16.394930]  bus_probe_device from deferred_probe_work_func+0x80/0xac[   16.396553]  deferred_probe_work_func from process_one_work+0x170/0x3c4[   16.398185]  process_one_work from worker_thread+0x26c/0x434[   16.399949]  worker_thread from kthread+0xe8/0x104[   16.401650]  kthread from ret_from_fork+0x14/0x28[   16.403213] Exception stack(0xbc179fb0 to 0xbc179ff8)[   16.404830] 9fa0:                                     00000000 00000000 00000000 00000000[   16.406485] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000[   16.408130] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000[   16.409796] Code: 15c4a00c e593503c 0a000033 e3e03001 (e58a3004)[   16.411621] ---[ end trace 0000000000000000 ]---