Backport fix max voltage (BPI R2)

[Josue-T]

Problème

On my side the kernel 6.1 crash with this following stacktrace:

[   17.002328] ------------[ cut here ]------------
[   17.006989] kernel BUG at drivers/regulator/core.c:424!
[   17.012235] Internal error: Oops - BUG: 0 [#1] SMP ARM
[   17.017391] Modules linked in: lima drm_shmem_helper gpu_sched spi_mt65xx pwm_mediatek sha1_arm sha256_arm sha512_arm aes_arm nf_conntrack_ftp ip6table_filter ip6_tables xt_state nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 fuse configfs ip_tables x_tables
[   17.040022] CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 6.1.22-bpi-r2-main #1
[   17.047266] Hardware name: Mediatek Cortex-A7 (Device Tree)
[   17.052853] Workqueue: events dbs_work_handler
[   17.057336] PC is at regulator_check_voltage+0xa8/0xec
[   17.062504] LR is at 0x118c30
[   17.065486] pc : [<c066bae0>]    lr : [<00118c30>]    psr: 200e0013
[   17.071763] sp : e087de00  ip : c19c4800  fp : c27d88b4
[   17.077007] r10: c1b15ec0  r9 : c2cb5a00  r8 : 00118c30
[   17.082268] r7 : c2606c00  r6 : 0013d620  r5 : 00000000  r4 : c2606c00
[   17.088818] r3 : c0670014  r2 : e087de18  r1 : e087de1c  r0 : c2606c00
[   17.095391] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   17.102610] Control: 10c5387d  Table: 886c806a  DAC: 00000051
[   17.108390] Register r0 information: slab kmalloc-1k start c2606c00 pointer offset 0 size 1024
[   17.117076] Register r1 information: 2-page vmalloc region starting at 0xe087c000 allocated at copy_process+0x1b8/0x10ec
[   17.128028] Register r2 information: 2-page vmalloc region starting at 0xe087c000 allocated at copy_process+0x1b8/0x10ec
[   17.138982] Register r3 information: non-slab/vmalloc memory
[   17.144689] Register r4 information: slab kmalloc-1k start c2606c00 pointer offset 0 size 1024
[   17.153355] Register r5 information: NULL pointer
[   17.158109] Register r6 information: non-paged memory
[   17.163206] Register r7 information: slab kmalloc-1k start c2606c00 pointer offset 0 size 1024
[   17.171873] Register r8 information: non-paged memory
[   17.176980] Register r9 information: slab kmalloc-64 start c2cb5a00 pointer offset 0 size 64
[   17.185487] Register r10 information: slab kmalloc-64 start c1b15ec0 pointer offset 0 size 64
[   17.194059] Register r11 information: slab kmalloc-192 start c27d8840 pointer offset 116 size 192
[   17.203003] Register r12 information: slab task_struct start c19c4800 pointer offset 0
[   17.210954] Process kworker/1:0 (pid: 20, stack limit = 0xb67caf0a)
[   17.217238] Stack: (0xe087de00 to 0xe087e000)
[   17.221628] de00: c2d0a980 00000000 0013d620 c2606c00 00118c30 c066e9b8 00118c30 0013d620
[   17.229881] de20: c2d0a980 00118c30 0013d620 0013d620 00118c30 c066ecd0 00124f80 c19c4800
[   17.238122] de40: 00000019 00000001 00000000 c654da05 c2d0ae00 c27d8880 00124f80 c0929e50
[   17.246336] de60: ded98050 c2c61800 3dfd2400 0013d620 4d7c6d00 c654da05 c1486140 c2c61800
[   17.254550] de80: 00000000 00000007 00000000 c14e703c 000fde80 0013d620 c1486140 c0922e6c
[   17.262767] dea0: dedb1470 c0cbe3e0 c129a370 ffffffff c2c61800 c2c61800 000fde80 0013d620
[   17.270980] dec0: 0000002c c654da05 dedb4305 c2c61800 c9469400 c9469580 c6099080 c9469400
[   17.279199] dee0: c9469580 dedb4305 c1473260 c09275b4 c946943c 00000000 c9469404 c2c61800
[   17.287397] df00: c144b604 c19c4800 dedb4305 c0928574 c946943c c1827c80 dedb10c0 dedb4300
[   17.295609] df20: 00000000 c0143dac c1827c98 c19c4800 dedb10c0 dedb10c0 dedb10dc c1827c80
[   17.303838] df40: dedb10c0 c1827c98 dedb10dc c1303d40 00000008 c19c4800 dedb10c0 c0144508
[   17.312050] df60: c19c4800 c14727b6 c1827c80 c19b7900 c19b7a80 e0825dec c19c4800 c01444ac
[   17.320247] df80: c1827c80 00000000 00000000 c014bd48 c19b7900 c014bc80 00000000 00000000
[   17.328443] dfa0: 00000000 00000000 00000000 c0100148 00000000 00000000 00000000 00000000
[   17.336637] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   17.344831] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[   17.353041]  regulator_check_voltage from regulator_set_voltage_unlocked+0xb4/0x124
[   17.360770]  regulator_set_voltage_unlocked from regulator_set_voltage+0x4c/0x8c
[   17.368204]  regulator_set_voltage from mtk_cpufreq_set_target+0xf8/0x394
[   17.375039]  mtk_cpufreq_set_target from __target_index+0x88/0x254
[   17.381254]  __target_index from od_dbs_update+0x150/0x17c
[   17.386771]  od_dbs_update from dbs_work_handler+0x34/0x60
[   17.392291]  dbs_work_handler from process_one_work+0x1c0/0x4a4
[   17.398247]  process_one_work from worker_thread+0x5c/0x50c
[   17.403850]  worker_thread from kthread+0xc8/0xcc
[   17.408582]  kthread from ret_from_fork+0x14/0x2c
[   17.413309] Exception stack(0xe087dfb0 to 0xe087dff8)
[   17.418378] dfa0:                                     00000000 00000000 00000000 00000000
[   17.426584] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   17.434794] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
[   17.441430] Code: e1500005 a1a05000 aafffff4 eafffff1 (e7f001f2)
[   17.447548] ---[ end trace 0000000000000000 ]---

It's also a known issue here: https://bugzilla.kernel.org/show_bug.cgi?id=216690

Solution

Backport the patch from the 6.3-rc kernel to the LTS kernel version to fix the issue.

I've tested on my BPI R2 and it fix the issue on my side.

[frank-w]

Hi,

Thx for tracing and reporting it

need to update lts branches in next time,maybe these patches already backported in higher dot release...

Have you tried merging latest 6.1.x from stable git?

Will merge the pr if it is still needed.

[Josue-T]

Hello,

I've checked and I as I see it's also backported on the last upstream release 6.1.x.

[frank-w]

i have merged stable 6.1.x into 6.1-main, so you can test with this base. if it is still not working you can rebase the PR to the new base

[Josue-T]

I've tested and it works so it's perfect. Thanks

[frank-w]

Thx for testing