RE: [PATCH net 2/2] net: fec: Reload PTP registers after link-state change

From: Wei Fang
Date: Tue Oct 08 2024 - 01:52:20 EST

Hi Guenter,

> On Tue, Sep 24, 2024 at 11:37:06AM +0200, Csókás, Bence wrote:
> > On link-state change, the controller gets reset,
> > which clears all PTP registers, including PHC time,
> > calibrated clock correction values etc. For correct
> > IEEE 1588 operation we need to restore these after
> > the reset.
> >
> > Fixes: 6605b730c061 ("FEC: Add time stamping code and a PTP hardware
> clock")
> > Signed-off-by: Csókás, Bence <csokas.bence@xxxxxxxxx>
> > ---
>
> This patch results in a lockdep splat and ultimately crashes.
> Seen when booting imx25-pdk (arm) and mcf5208evb (m68k) in qemu.
>
> Crash and bisect log attached.
>
> Guenter
> ---
>
> imx25-pdk (arm):
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?

Yes, you are right, fec_ptp_init() is not called on i.mx25 platform,
so fep->tmreg_lock and fep->cc are not initialized, but fec_ptp_save_state()
is still called, which causes this issue. I will fix the issue ASAP.
Thanks!

> turning off the locking correctness validator.
> CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc2 #1
> Hardware name: Freescale i.MX25 (Device Tree Support)
> Call trace:
> unwind_backtrace from show_stack+0x10/0x18
> show_stack from dump_stack_lvl+0x40/0x68
> dump_stack_lvl from register_lock_class+0x6a8/0x724
> register_lock_class from __lock_acquire+0x8c/0x24c4
> __lock_acquire from lock_acquire+0x114/0x360
> lock_acquire from _raw_spin_lock_irqsave+0x58/0x78
> _raw_spin_lock_irqsave from fec_ptp_save_state+0x14/0x6c
> fec_ptp_save_state from fec_restart+0x2c/0x740
> fec_restart from fec_probe+0xd40/0x16f0
> fec_probe from platform_probe+0x5c/0xc4
> platform_probe from really_probe+0xd0/0x2a8
> really_probe from __driver_probe_device+0x80/0x19c
> __driver_probe_device from driver_probe_device+0x44/0x108
> driver_probe_device from __driver_attach+0x74/0x114
> __driver_attach from bus_for_each_dev+0x74/0xcc
> bus_for_each_dev from driver_attach+0x18/0x24
> driver_attach from bus_add_driver+0xc8/0x1f0
> bus_add_driver from driver_register+0x7c/0x120
> driver_register from __platform_driver_register+0x18/0x24
> __platform_driver_register from fec_driver_init+0x10/0x1c
> fec_driver_init from do_one_initcall+0x5c/0x2f4
> do_one_initcall from kernel_init_freeable+0x190/0x21c
> kernel_init_freeable from kernel_init+0x10/0x110
> kernel_init from ret_from_fork+0x14/0x38
> Exception stack(0xc8825fb0 to 0xc8825ff8)
> 5fa0: 00000000 00000000
> 00000000 00000000
> 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> 8<--- cut here ---
> Unable to handle kernel NULL pointer dereference at virtual address 00000000
> when read
> [00000000] *pgd=00000000
> Internal error: Oops: 5 [#1] PREEMPT ARM
> Modules linked in:
> CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc2 #1
> Hardware name: Freescale i.MX25 (Device Tree Support)
> PC is at timecounter_read+0xc/0xbc
> LR is at fec_ptp_save_state+0x28/0x6c
> pc : [<c00cdfac>] lr : [<c08a00a4>] psr: 60000193
> sp : c8825c98 ip : 00000000 fp : c1ddc6a0
> r10: 00000000 r9 : c18c73a0 r8 : c1f68410
> r7 : c7ef4a38 r6 : c1ddc904 r5 : 40000113 r4 : c1ddc940
> r3 : 00000000 r2 : 00000000 r1 : 00000001 r0 : 00000000
> Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none
> Control: 00093177 Table: 80004000 DAC: 00000053
> Register r0 information: NULL pointer
> Register r1 information: non-paged memory
> Register r2 information: NULL pointer
> Register r3 information: NULL pointer
> Register r4 information: slab kmalloc-4k start c1ddb000 data offset 4096
> pointer offset 2368 size 4096 allocated at
> __kvmalloc_node_noprof+0x14/0x108
> __kmalloc_node_noprof+0x3a0/0x50c
> __kvmalloc_node_noprof+0x14/0x108
> alloc_netdev_mqs+0x58/0x44c
> alloc_etherdev_mqs+0x1c/0x30
> fec_probe+0x54/0x16f0
> platform_probe+0x5c/0xc4
> really_probe+0xd0/0x2a8
> __driver_probe_device+0x80/0x19c
> driver_probe_device+0x44/0x108
> __driver_attach+0x74/0x114
> bus_for_each_dev+0x74/0xcc
> driver_attach+0x18/0x24
> bus_add_driver+0xc8/0x1f0
> driver_register+0x7c/0x120
> __platform_driver_register+0x18/0x24
> fec_driver_init+0x10/0x1c
> Free path:
> kobject_uevent_env+0x10c/0x55c
> driver_register+0xb0/0x120
> __platform_driver_register+0x18/0x24
> dm9000_driver_init+0x10/0x1c
> do_one_initcall+0x5c/0x2f4
> kernel_init_freeable+0x190/0x21c
> kernel_init+0x10/0x110
> ret_from_fork+0x14/0x38
> Register r5 information: non-paged memory
> Register r6 information: slab kmalloc-4k start c1ddb000 data offset 4096
> pointer offset 2308 size 4096 allocated at
> __kvmalloc_node_noprof+0x14/0x108
> __kmalloc_node_noprof+0x3a0/0x50c
> __kvmalloc_node_noprof+0x14/0x108
> alloc_netdev_mqs+0x58/0x44c
> alloc_etherdev_mqs+0x1c/0x30
> fec_probe+0x54/0x16f0
> platform_probe+0x5c/0xc4
> really_probe+0xd0/0x2a8
> __driver_probe_device+0x80/0x19c
> driver_probe_device+0x44/0x108
> __driver_attach+0x74/0x114
> bus_for_each_dev+0x74/0xcc
> driver_attach+0x18/0x24
> bus_add_driver+0xc8/0x1f0
> driver_register+0x7c/0x120
> __platform_driver_register+0x18/0x24
> fec_driver_init+0x10/0x1c
> Free path:
> kobject_uevent_env+0x10c/0x55c
> driver_register+0xb0/0x120
> __platform_driver_register+0x18/0x24
> dm9000_driver_init+0x10/0x1c
> do_one_initcall+0x5c/0x2f4
> kernel_init_freeable+0x190/0x21c
> kernel_init+0x10/0x110
> ret_from_fork+0x14/0x38
> Register r7 information: non-slab/vmalloc memory
> Register r8 information: slab kmalloc-1k start c1f68000 data offset 1024
> pointer offset 16 size 1024 allocated at platform_device_alloc+0x20/0xc4
> __kmalloc_noprof+0x39c/0x508
> platform_device_alloc+0x20/0xc4
> of_device_alloc+0x30/0x174
> of_platform_device_create_pdata+0x60/0x104
> of_platform_bus_create+0x198/0x25c
> of_platform_bus_create+0x1e4/0x25c
> of_platform_bus_create+0x1e4/0x25c
> of_platform_populate+0x78/0xfc
> of_platform_default_populate_init+0xc8/0xe8
> do_one_initcall+0x5c/0x2f4
> kernel_init_freeable+0x190/0x21c
> kernel_init+0x10/0x110
> ret_from_fork+0x14/0x38
> Register r9 information: non-slab/vmalloc memory
> Register r10 information: NULL pointer
> Register r11 information: slab kmalloc-4k start c1ddb000 data offset 4096
> pointer offset 1696 size 4096 allocated at
> __kvmalloc_node_noprof+0x14/0x108
> __kmalloc_node_noprof+0x3a0/0x50c
> __kvmalloc_node_noprof+0x14/0x108
> alloc_netdev_mqs+0x58/0x44c
> alloc_etherdev_mqs+0x1c/0x30
> fec_probe+0x54/0x16f0
> platform_probe+0x5c/0xc4
> really_probe+0xd0/0x2a8
> __driver_probe_device+0x80/0x19c
> driver_probe_device+0x44/0x108
> __driver_attach+0x74/0x114
> bus_for_each_dev+0x74/0xcc
> driver_attach+0x18/0x24
> bus_add_driver+0xc8/0x1f0
> driver_register+0x7c/0x120
> __platform_driver_register+0x18/0x24
> fec_driver_init+0x10/0x1c
> Free path:
> kobject_uevent_env+0x10c/0x55c
> driver_register+0xb0/0x120
> __platform_driver_register+0x18/0x24
> dm9000_driver_init+0x10/0x1c
> do_one_initcall+0x5c/0x2f4
> kernel_init_freeable+0x190/0x21c
> kernel_init+0x10/0x110
> ret_from_fork+0x14/0x38
> Register r12 information: NULL pointer
> Process swapper (pid: 1, stack limit = 0xc8824000)
> Stack: (0xc8825c98 to 0xc8826000)
> 5c80:
> c1ddc6a0 40000113
> 5ca0: c1ddc904 c7ef4a38 c1f68410 c08a00a4 c1ddc000 c1ddc000 c1f68400
> c0899dd8
> 5cc0: c1ddc84c c012856c c1d74800 c0a329c8 00000001 c1ddc6a0 c1ddc0f8
> c002222c
> 5ce0: c1ddc780 c1ddc000 c11a4e58 c0a32a08 c1ddc780 c10db96c c1ddc6a0
> c1ddc000
> 5d00: 00000000 c1f68400 c7ef4a38 c1f68410 c18c73a0 00000000 c1ddc6a0
> c089da94
> 5d20: 00000000 c8825d7c c0f6c1c0 c11a14a0 00000000 00000000
> 00000001 00000008
> 5d40: c1ddc780 fffffff8 c0ccd84a c8825dcc 00000003 00000008 c7ef4a38
> c0ccd5b4
> 5d60: c7ef4a38 00000000 00000007 00000001 00000001 00000001
> 82902800 c0f8be54
> 5d80: 00000000 c02995e0 c28d4bb8 00000000 c1d2ce7c c02996f0
> c1f17848 c28d4bb8
> 5da0: c1f17848 c0299200 00000000 c28d4bb8 c28d4848 c1f17848 c0fbe7ec
> 00000000
> 5dc0: c28d4848 54524bb8 56341200 12005452 c1f15634 c10db96c
> 00000000 00000000
> 5de0: c1f68410 c1195160 00000000 c28d6858 c0fce780 c10b5854
> 00000000 c07b0790
> 5e00: 00000000 c1f68410 c1195160 c07ade1c c1f68410 c1195160 c1f68410
> 00000000
> 5e20: c28d6858 c07ae074 60000113 c11a14a0 c7ef4a38 c18c5520
> 60000113 c1f68410
> 5e40: 00000000 c28d6858 c0fce780 c10b5854 00000000 c07ae224
> 00000000 c0c288fc
> 5e60: c07ad13c c1f68410 c1195160 c07ae3bc c1d82c00 c07ae430 00000000
> c1195160
> 5e80: c07ae3bc c07abd24 c1d82d04 c1d82cac c1f151d4 c10db96c c1d82ce0
> c1195160
> 5ea0: c28d6800 00000000 c1d82c00 c07ad6a4 c1195160 c07acee0 c0f67004
> c0fce780
> 5ec0: c1195160 c1d74800 c11ca0a0 00000000 c102dbc4 c07af1dc c10a2998
> c1d74800
> 5ee0: c11ca0a0 c07b05cc c10a2998 c10a29a8 c10a2998 c0009f70 00000000
> 00000000
> 5f00: c1d602bf c102f300 00000135 c004553c c102dbc4 c0f995e4 c1072400
> 00000000
> 5f20: 00000006 00000006 00000060 c1d602a9 c1d602b1 c10db96c
> c0fce780 00000006
> 5f40: 00000135 c10db96c 00000006 c10d2248 00000007 c1d60260
> c10b5874 c1073284
> 5f60: 00000006 00000006 00000000 c1072400 00000000 00000135
> 00000000 00000000
> 5f80: c0c22ac4 00000000 00000000 00000000 00000000 00000000
> 00000000 c0c22ad4
> 5fa0: 00000000 c0c22ac4 00000000 c000851c 00000000 00000000
> 00000000 00000000
> 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> 00000000 00000000
> Call trace:
> timecounter_read from fec_ptp_save_state+0x28/0x6c
> fec_ptp_save_state from fec_restart+0x2c/0x740
> fec_restart from fec_probe+0xd40/0x16f0
> fec_probe from platform_probe+0x5c/0xc4
> platform_probe from really_probe+0xd0/0x2a8
> really_probe from __driver_probe_device+0x80/0x19c
> __driver_probe_device from driver_probe_device+0x44/0x108
> driver_probe_device from __driver_attach+0x74/0x114
> __driver_attach from bus_for_each_dev+0x74/0xcc
> bus_for_each_dev from driver_attach+0x18/0x24
> driver_attach from bus_add_driver+0xc8/0x1f0
> bus_add_driver from driver_register+0x7c/0x120
> driver_register from __platform_driver_register+0x18/0x24
> __platform_driver_register from fec_driver_init+0x10/0x1c
> fec_driver_init from do_one_initcall+0x5c/0x2f4
> do_one_initcall from kernel_init_freeable+0x190/0x21c
> kernel_init_freeable from kernel_init+0x10/0x110
> kernel_init from ret_from_fork+0x14/0x38
> Exception stack(0xc8825fb0 to 0xc8825ff8)
> 5fa0: 00000000 00000000
> 00000000 00000000
> 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> Code: e12fff1e e92d41f0 e1a04000 e5900000 (e5903000)
> ---[ end trace 0000000000000000 ]---
> note: swapper[1] exited with irqs disabled
> note: swapper[1] exited with preempt_count 1
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
>
> mcf5208evb (m68k):
>
> *** ILLEGAL INSTRUCTION *** FORMAT=4
> Current process id is 1
> BAD KERNEL TRAP: 00000000
> PC: [<00000000>] 0x0
> SR: 2704 SP: (ptrval) a2: 40841678
> d0: 00002700 d1: 00000000 d2: 403b2000 d3: 00000000
> d4: 00000000 d5: 40344cd0 a0: 00000000 a1: 00000018
> Process swapper (pid: 1, task=(ptrval))
> Frame format=4 eff addr=4006f5ea pc=00000000
> Stack from 4081fd50:
> 403b2000 00000000 40344b8c 40344cd0 40021ae2 fffffff8
> 40841460 40841000
> 401dfa1e 40841678 403b5fc2 403b5fb8 401dacd8 40841460
> 403b5fc2 00000000
> 40344b8c 40344cd0 40021ae2 fffffff8 403b5fb8 40841000 408414fc
> 40344b82
> 4081fe24 40841460 00000000 00000000 401dbd90 40841000
> 00000000 00000000
> 4031c96e 00000000 00000000 403e8bf8 403b5fc2 403d3f54
> 401bb68a 403eeb0a
> 400a2aec 00000000 00000008 00000003 00000003 4084149a
> 00000000 40c2a800
> Call Trace: [<40021ae2>] clk_get_rate+0x0/0x12
> [<401dfa1e>] fec_ptp_save_state+0x24/0x5c
> [<401dacd8>] fec_restart+0x24/0x7b0
> [<40021ae2>] clk_get_rate+0x0/0x12
> [<401dbd90>] fec_probe+0x6fe/0xe2c
> [<4031c96e>] strcpy+0x0/0x18
> [<403e8bf8>] fec_driver_init+0x0/0x12
> [<401bb68a>] bus_notify+0x0/0x4e
> [<400a2aec>] __kmalloc_cache_noprof+0x0/0x15a
> [<401be2cc>] platform_probe+0x22/0x58
> [<401bbf4e>] really_probe+0xa0/0x2aa
> [<4032fa5a>] mutex_lock+0x0/0x36
> [<401bc4f0>] driver_probe_device+0x24/0x112
> [<4032f5ca>] mutex_unlock+0x0/0x38
> [<401bc80e>] __driver_attach+0xe6/0x1d0
> [<402fefd4>] klist_next+0x0/0x140
> [<401bc728>] __driver_attach+0x0/0x1d0
> [<401ba576>] bus_for_each_dev+0x6e/0xca
> [<401bba5e>] driver_attach+0x16/0x1c
> [<401bc728>] __driver_attach+0x0/0x1d0
> [<401bb4ae>] bus_add_driver+0x12e/0x20e
> [<401bd28e>] driver_register+0x4c/0xd4
> [<401bd29c>] driver_register+0x5a/0xd4
> [<403e8c06>] fec_driver_init+0xe/0x12
> [<403dab82>] do_one_initcall+0x74/0x250
> [<4031c96e>] strcpy+0x0/0x18
> [<400400d8>] parse_args+0x0/0x374
> [<403daf02>] kernel_init_freeable+0x14c/0x19c
> [<403e8bf8>] fec_driver_init+0x0/0x12
> [<40326a8a>] _printk+0x0/0x18
> [<4032d026>] kernel_init+0x0/0xf0
> [<4032d040>] kernel_init+0x1a/0xf0
> [<400204a0>] ret_from_kernel_thread+0xc/0x14
> Code: 0000 0000 0000 0000 0000 0000 0000 0000 <0000> 0000 0000 0000
> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
> Disabling lock debugging due to kernel taint
> note: swapper[1] exited with irqs disabled
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
>
> ---
> # bad: [8cf0b93919e13d1e8d4466eb4080a4c4d9d66d7b] Linux 6.12-rc2
> # good: [9852d85ec9d492ebef56dc5f229416c925758edc] Linux 6.12-rc1
> git bisect start 'HEAD' 'v6.12-rc1'
> # bad: [fe6fceceaecf4c7488832be18a37ddf9213782bc] Merge tag
> 'drm-fixes-2024-10-04' of
> https://gitlab.fr/
> eedesktop.org%2Fdrm%2Fkernel&data=05%7C02%7Cwei.fang%40nxp.com%7
> Ca582618b128e40fda60308dce6f00130%7C686ea1d3bc2b4c6fa92cd99c5c3
> 01635%7C0%7C0%7C638639165713892201%7CUnknown%7CTWFpbGZsb3d
> 8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3
> D%7C0%7C%7C%7C&sdata=07kr3KH0waKzoZkAYyLQ6YB0Ep4S1kVPSaVUBtUS
> G4o%3D&reserved=0
> git bisect bad fe6fceceaecf4c7488832be18a37ddf9213782bc
> # bad: [8c245fe7dde3bf776253550fc914a36293db4ff3] Merge tag
> 'net-6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
> git bisect bad 8c245fe7dde3bf776253550fc914a36293db4ff3
> # good: [9c02404b52f56b2c8acc8c0ac16d525b1226dfe5] Merge tag
> 'v6.12-rc1-ksmbd-fixes' of git://git.samba.org/ksmbd
> git bisect good 9c02404b52f56b2c8acc8c0ac16d525b1226dfe5
> # bad: [e5e3f369b123a7abe83fb6f5f9eab6651ee9b76b] Merge tag
> 'for-net-2024-09-27' of
> git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth
> git bisect bad e5e3f369b123a7abe83fb6f5f9eab6651ee9b76b
> # bad: [c20029db28399ecc50e556964eaba75c43b1e2f1] net: avoid potential
> underflow in qdisc_pkt_len_init() with UFO
> git bisect bad c20029db28399ecc50e556964eaba75c43b1e2f1
> # good: [e609c959a939660c7519895f853dfa5624c6827a] net: Fix
> gso_features_check to check for both dev->gso_{ipv4_,}max_size
> git bisect good e609c959a939660c7519895f853dfa5624c6827a
> # good: [a1477dc87dc4996dcf65a4893d4e2c3a6b593002] net: fec: Restart
> PPS after link state change
> git bisect good a1477dc87dc4996dcf65a4893d4e2c3a6b593002
> # bad: [1910bd470a0acea01b88722be61f0dfa29089730] net: microchip:
> Make FDMA config symbol invisible
> git bisect bad 1910bd470a0acea01b88722be61f0dfa29089730
> # bad: [d9335d0232d2da605585eea1518ac6733518f938] net: fec: Reload PTP
> registers after link-state change
> git bisect bad d9335d0232d2da605585eea1518ac6733518f938
> # first bad commit: [d9335d0232d2da605585eea1518ac6733518f938] net:
> fec: Reload PTP registers after link-state change