Re: [BUG] Usb fingerprint sensor constantly resetting on MSI Prestige 16 Flip AI+ C3MTG

[EricLin <ericlin050914@gmail.com>]

> So maybe it's just the userspace software doing it for whatever reason
> on every use. Guess you could run "strace -eioctl" on this program to
> see if there is USBDEVFS_RESET each time the dmesg message shows up.

Here are the outputs of strace

$ strace -eioctl fprintd-verify
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Using device /net/reactivated/Fprint/Device/0
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Listing enrolled fingers:
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
 - #0: right-index-finger
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Verify started!
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Verifying: right-index-finger
ioctl(1, TCGETS2, {c_iflag=ICRNL|IXON|IUTF8, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Verify result: verify-match (done)
+++ exited with 0 +++

> Or add dump_stack() in usb_reset_device(), recompile and see what pops
> up. Probably ioctl syscall at the bottom of the call stack...

I changed the hub.c code like this

int usb_reset_device(struct usb_device *udev)
{
	int ret;
	int i;
	unsigned int noio_flag;
	struct usb_port *port_dev;
	struct usb_host_config *config = udev->actconfig;
	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);

	dump_stack();
	// remaining code
}

And here are the outputs of dmesg

[  146.079223] CPU: 0 UID: 0 PID: 3544 Comm: fprintd Tainted: G        W           7.3.0-rc3-1-cachyos-rc #2 PREEMPT(full)  ca2d5051c95b910bac0a8f0497b52243cdaa75fa
[  146.079237] Tainted: [W]=WARN
[  146.079239] Hardware name: Micro-Star International Co., Ltd. Prestige 16 Flip AI+ C3MTG/MS-2622, BIOS E2622IMS.11A 08/12/2026
[  146.079242] Call Trace:
[  146.079247]  <TASK>
[  146.079253]  dump_stack_lvl+0x61/0x80
[  146.079267]  usb_reset_device+0x4f/0x2b0
[  146.079274]  usbdev_ioctl+0x836/0xd80
[  146.079282]  __x64_sys_ioctl+0x76/0xc0
[  146.079290]  do_syscall_64+0x100/0x360
[  146.079297]  ? do_syscall_64+0x13b/0x360
[  146.079300]  ? do_file_open+0xd7/0x190
[  146.079307]  ? __kmalloc_node_noprof+0x317/0x520
[  146.079313]  ? alloc_cpumask_var_node+0x22/0x40
[  146.079319]  ? task_cache_work+0x614/0x640
[  146.079329]  ? exit_to_user_mode_loop+0x14c/0x820
[  146.079338]  ? current_time+0x39/0x150
[  146.079348]  ? usbdev_ioctl+0x291/0xd80
[  146.079358]  ? __x64_sys_ioctl+0xb8/0xc0
[  146.079370]  ? do_syscall_64+0x13b/0x360
[  146.079377]  ? wake_up_q+0x5c/0x90
[  146.079388]  ? futex_wake+0x1c6/0x200
[  146.079401]  ? do_futex+0x127/0x200
[  146.079408]  ? __se_sys_futex+0x13d/0x1d0
[  146.079418]  ? do_syscall_64+0x13b/0x360
[  146.079424]  ? irqentry_exit+0x3f/0x830
[  146.079433]  ? do_syscall_64+0x42/0x360
[  146.079440]  ? __irq_exit_rcu.llvm.4659499815316783039+0x6b/0x120
[  146.079454]  asm_fred_entrypoint_user+0x41/0x41
[  146.079463] RIP: 0033:0x7a72c4b0b62d
[  146.079563] Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10 c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1a 48 8b 45 c8 64 48 2b 04 25 28 00 00 00
[  146.079571] RSP: 002b:00007ffc6ad1fd20 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  146.079585] RAX: ffffffffffffffda RBX: 0000000000000020 RCX: 0000000000000dd8
[  146.079589] RDX: 0000000000000000 RSI: 0000000000005514 RDI: 000000000000000b
[  146.079592] RBP: 00007ffc6ad1fd70 R08: 00007ffc6ad1fcc0 R09: 0000000000000000
[  146.079594] R10: 0000000000000001 R11: 0000000000000000 R12: 00007a72a4005610
[  146.079596] R13: 0000000000000000 R14: 000000000000000b R15: 00007a72a40017c0
[  146.079602]  </TASK>
[  146.191449] usb 3-6: reset full-speed USB device number 2 using xhci_hcd

Regards,
Eric