Hi!

I'm currently trying to get the latest linux-rt kernel (v5.9.1-rt18) to
work on my AMD hardware. I'm providing the kernel as a prebuilt binary
to the Arch Linux community, as we do not have that specific kernel in
the repositories (yet).

I'm facing issues in regards to hardware discovery and crashes, which I
do not get on the vanilla kernel (now at 5.9.1) on Arch Linux.

I have a PCIe Firewire card that I use for an external audio interface
(RME Fireface800):

05:00.0 FireWire (IEEE 1394): Texas Instruments XIO2213A/B/XIO2221
IEEE-1394b OHCI Controller [Cheetah Express] (rev 01)

Unfortunately the card does not show up anymore and instead I run into a
bug:

Oct 21 19:08:03 hmbx kernel: ------------[ cut here ]------------
Oct 21 19:08:03 hmbx kernel: DEBUG_LOCKS_WARN_ON(val > preempt_count())
Oct 21 19:08:03 hmbx kernel: WARNING: CPU: 19 PID: 0 at
kernel/sched/core.c:4763 preempt_count_sub+0x5a/0x90
Oct 21 19:08:03 hmbx kernel: Modules linked in: crypto_user ip_tables
x_tables dm_crypt encrypted_keys trusted tpm hid_logitech_hidpp
hid_logitech_dj sd_mod hid_generic usbhid hid amdgpu gpu_sched ttm
drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
crct10dif_pclmul cec ahci r8169 crc32_pclmul ghash_clmuln
i_intel libahci realtek aesni_intel mdio_devres crypto_simd dm_mod btrfs
of_mdio firewire_ohci blake2b_generic drm libcrc32c cryptd libata ccp
xhci_pci fixed_phy crc32c_generic ehci_pci igb glue_helper firewire_core
crc32c_intel agpgart rng_core crc_itu_t scsi_mod xhci_hcd xor dca libphy
ehci_hcd i2c_algo_bit wmi raid
6_pq
Oct 21 19:08:03 hmbx kernel: CPU: 19 PID: 0 Comm: swapper/19 Tainted: G
W         5.9.1-rt18-1-rt #1
Oct 21 19:08:03 hmbx kernel: Hardware name: System manufacturer System
Product Name/Pro WS X570-ACE, BIOS 1302 01/20/2020
Oct 21 19:08:03 hmbx kernel: RIP: 0010:preempt_count_sub+0x5a/0x90
Oct 21 19:08:03 hmbx kernel: Code: 2d d5 62 c3 e8 a7 2d 8c 00 85 c0 74
f6 8b 15 55 77 50 01 85 d2 75 ec 48 c7 c6 df 5c 30 9e 48 c7 c7 ea e9 2e
9e e8 ab ee fc ff <0f> 0b c3 84 c0 75 c9 e8 7a 2d 8c 00 85 c0 74 c9 8b
05 28 77 50 01
Oct 21 19:08:03 hmbx kernel: RSP: 0018:ffff9304401e7dc0 EFLAGS: 00010082
Oct 21 19:08:03 hmbx kernel: RAX: 0000000000000000 RBX: ffff90e257e53f00
RCX: 0000000000000000
Oct 21 19:08:03 hmbx kernel: RDX: 0000000000000001 RSI: ffffffff9e313727
RDI: 00000000ffffffff
Oct 21 19:08:03 hmbx kernel: RBP: ffff9304401e7df8 R08: ffffffff9ed443e0
R09: 0000000000000001
Oct 21 19:08:03 hmbx kernel: R10: ffff9304401e7ce8 R11: 3fffffffffffffff
R12: 0000000000000001
Oct 21 19:08:03 hmbx kernel: R13: 0000000000000000 R14: 0000000000000000
R15: 0000000000000000
Oct 21 19:08:03 hmbx kernel: FS:  0000000000000000(0000)
GS:ffff90e25eec0000(0000) knlGS:0000000000000000
Oct 21 19:08:03 hmbx kernel: CS:  0010 DS: 0000 ES: 0000 CR0:
0000000080050033
Oct 21 19:08:03 hmbx kernel: CR2: 00007f085fb38c20 CR3: 0000000fb829c000
CR4: 0000000000350ee0
Oct 21 19:08:03 hmbx kernel: Call Trace:
Oct 21 19:08:03 hmbx kernel:  irq_exit_rcu+0x28/0xe0
Oct 21 19:08:03 hmbx kernel:  sysvec_call_function_single+0x47/0xe0
Oct 21 19:08:03 hmbx kernel:  asm_sysvec_call_function_single+0x12/0x20
Oct 21 19:08:03 hmbx kernel: RIP: 0010:cpuidle_enter_state+0xd9/0x440
Oct 21 19:08:03 hmbx kernel: Code: 95 ff 49 89 c5 8b 05 6e ad e2 00 85
c0 0f 8f f1 01 00 00 31 ff e8 c7 26 95 ff 45 84 f6 0f 85 9f 01 00 00 fb
66 0f 1f 44 00 00 <45> 85 e4 0f 88 de 00 00 00 49 63 d4 4d 29 fd 48 8d
04 52 48 8d 04
Oct 21 19:08:03 hmbx kernel: RSP: 0018:ffff9304401e7ea0 EFLAGS: 00000246
Oct 21 19:08:03 hmbx kernel: RAX: ffff90e25eec0000 RBX: ffff90e240dc7400
RCX: 000000000000001f
Oct 21 19:08:03 hmbx kernel: RDX: 0000000000000001 RSI: ffffffff9e313727
RDI: ffffffff9e340fb6
Oct 21 19:08:03 hmbx kernel: RBP: ffffffff9e745bc0 R08: 0000000000000002
R09: 0000000000000020
Oct 21 19:08:03 hmbx kernel: R10: 0000000000000165 R11: 0000000000006045
R12: 0000000000000002
Oct 21 19:08:03 hmbx kernel: R13: 0000000398671b89 R14: 0000000000000000
R15: 00000003986701bf
Oct 21 19:08:03 hmbx kernel:  cpuidle_enter+0x29/0x40
Oct 21 19:08:03 hmbx kernel:  do_idle+0x232/0x2d0
Oct 21 19:08:03 hmbx kernel:  cpu_startup_entry+0x19/0x20
Oct 21 19:08:03 hmbx kernel:  secondary_startup_64+0xb6/0xc0
Oct 21 19:08:03 hmbx kernel: ---[ end trace 0000000000000002 ]---

I have the kernel log and lspci output (from the working vanilla kernel)
here: https://pkgbuild.com/~dvzrv/bugs/linux-rt-5.9.1.18/

Any pointers or help would be much appreciated! If you need more
information, just ask! :)

Best,
David

P.S.: I was trying the 5.6.x series of realtime kernels on this machine
as well, but although the hardware gets initialized properly (at least
without crashes) my system completely freezes as soon as I start jackd
on the firewire interface (this does not happen with a non-rt kernel).

-- 
https://sleepmap.de