Re: [PATCH v2 0/5] tpm_tis: fix interrupts (again)

[Jerry Snitselaar <jsnitsel@redhat.com>]

James Bottomley @ 2020-10-01 11:09 MST:

> The current state of the TIS TPM is that interrupts have been globally
> disabled by various changes.  The problems we got reported the last
> time they were enabled was interrupt storms.  With my own TIS TPM,
> I've found that this is caused because my TPM doesn't do legacy
> cycles, The TIS spec (chapter 6.1 "Locality Usage Per Register")
> requires any TIS TPM without legacy cycles not to act on any write to
> an interrupt register unless the locality is enabled.  This means if
> an interrupt fires after we relinquish the locality, the TPM_EOI in
> the interrupt routine is ineffective meaning the same interrupt
> triggers over and over again.  This problem also means we can have
> trouble setting up interrupts on TIS TPMs because the current init
> code does the setup before the locality is claimed for the first time.
>
> James
>


I tested initially with the following commits reverted:

aa4a63dd9816 tpm: Revert "tpm_tis_core: Turn on the TPM before probing IRQ's" | 2020-01-06 | (Stefan Berger)
dda8b2af395b tpm: Revert "tpm_tis_core: Set TPM_CHIP_FLAG_IRQ before probing for interrupts" | 2020-01-06 | (Stefan Berger)

The laptop doesn't become unusable, but I lose the trackpad and get the following:

[    3.070501] irq 31: nobody cared (try booting with the "irqpoll" option)
[    3.070504] CPU: 2 PID: 251 Comm: rngd Not tainted 5.8.13-201.local.fc32.x86_64 #1
[    3.070504] Hardware name: LENOVO 20NYS7K90F/20NYS7K90F, BIOS N2JET83W (1.61 ) 11/22/2019
[    3.070505] Call Trace:
[    3.070511]  dump_stack+0x6b/0x88
[    3.070514]  __report_bad_irq+0x35/0xa7
[    3.070516]  note_interrupt.cold+0xb/0x6a
[    3.070518]  handle_irq_event+0x88/0x8a
[    3.070519]  handle_fasteoi_irq+0x78/0x1c0
[    3.070522]  common_interrupt+0x68/0x140
[    3.070524]  ? asm_common_interrupt+0x8/0x40
[    3.070525]  asm_common_interrupt+0x1e/0x40
[    3.070527] RIP: 0033:0x7f2eea3249b5
[    3.070529] Code: e0 48 c1 e8 3c 83 e0 01 48 31 45 f0 48 8b 45 e0 48 c1 e8 37 83 e0 01 48 31 45 f0 48 8b 45 e0 48 c1 e8 1e 83 e0 01 48 31 45 f0 <48> 8b 45 e0 48 c1 e8 1b 83 e0 01 48 31 45 f0 48 8b 45 e0 48 c1 e8
[    3.070529] RSP: 002b:00007f2ee3ffebc0 EFLAGS: 00000202
[    3.070530] RAX: 0000000000000001 RBX: 000000000000000a RCX: 000000000000002e
[    3.070531] RDX: 0463400000000000 RSI: 0000000000000000 RDI: 0000000000000001
[    3.070532] RBP: 00007f2ee3ffec10 R08: 0000000000000000 R09: 0000000000000035
[    3.070532] R10: 00007ffde716f080 R11: 00007ffde716f080 R12: 00007f2edc004c00
[    3.070533] R13: 00007ffde700a54f R14: 00007f2ee3ffed10 R15: 00005598a41e3680
[    3.070534] handlers:
[    3.070537] [<000000007b6f3232>] tis_int_handler
[    3.070538] Disabling IRQ #31
...
[   14.956342] irq 16: nobody cared (try booting with the "irqpoll" option)
[   14.956344] CPU: 0 PID: 1013 Comm: rngd Not tainted 5.8.13-201.local.fc32.x86_64 #1
[   14.956344] Hardware name: LENOVO 20NYS7K90F/20NYS7K90F, BIOS N2JET83W (1.61 ) 11/22/2019
[   14.956345] Call Trace:
[   14.956350]  dump_stack+0x6b/0x88
[   14.956353]  __report_bad_irq+0x35/0xa7
[   14.956354]  note_interrupt.cold+0xb/0x6a
[   14.956355]  handle_irq_event+0x88/0x8a
[   14.956356]  handle_fasteoi_irq+0x78/0x1c0
[   14.956358]  common_interrupt+0x68/0x140
[   14.956360]  ? asm_common_interrupt+0x8/0x40
[   14.956361]  asm_common_interrupt+0x1e/0x40
[   14.956362] RIP: 0033:0x7fcaff4399d3
[   14.956363] Code: e0 48 c1 e8 1e 83 e0 01 48 31 45 f0 48 8b 45 e0 48 c1 e8 1b 83 e0 01 48 31 45 f0 48 8b 45 e0 48 c1 e8 16 83 e0 01 48 31 45 f0 <48> d1 65 e0 48 8b 45 f0 48 31 45 e0 83 45 d4 01 83 7d d4 40 0f 86
[   14.956364] RSP: 002b:00007fcafe544bc0 EFLAGS: 00000246
[   14.956364] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000026
[   14.956365] RDX: 000df20000000000 RSI: 0000000000000000 RDI: 0000000000000001
[   14.956365] RBP: 00007fcafe544c10 R08: 0000000000000000 R09: 0000000000000035
[   14.956366] R10: 00007ffc30bd2080 R11: 00007ffc30bd2080 R12: 00007fcaf0004c00
[   14.956366] R13: 00007fcaf0004c00 R14: 00007fcaf0000b60 R15: 0000560216fcf0f2
[   14.956367] handlers:
[   14.956370] [<0000000024c0571e>] i801_isr [i2c_i801]
[   14.956371] Disabling IRQ #16

/proc/interrupts shows:

  16:     100000          0          0          0          0          0          0          0  IR-IO-APIC   16-fasteoi   i801_smbus
  31:          0          0     100000          0          0          0          0          0  IR-IO-APIC   31-fasteoi   tpm0


I also get this behavior with your patchset applied. If I boot with
tpm_tis.interrupts=0 it behaves.  The thought from Hans is to look at
the dmi info and key off the vendor being Lenovo and bios date to
decide if interrupts should be disabled. Since Dan ran also into this
with something internal at Intel I don't know if that will be
sufficient.

I hope to look over this patchset tomorrow.

Regards,
Jerry