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Commit 481c2d14 authored by Lino Sanfilippo's avatar Lino Sanfilippo Committed by Jarkko Sakkinen
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tpm,tpm_tis: Disable interrupts after 1000 unhandled IRQs



After activation of interrupts for TPM TIS drivers 0-day reports an
interrupt storm on an Inspur NF5180M6 server.

Fix this by detecting the storm and falling back to polling:
Count the number of unhandled interrupts within a 10 ms time interval. In
case that more than 1000 were unhandled deactivate interrupts entirely,
deregister the handler and use polling instead.

Also print a note to point to the tpm_tis_dmi_table.

Since the interrupt deregistration function devm_free_irq() waits for all
interrupt handlers to finish, only trigger a worker in the interrupt
handler and do the unregistration in the worker to avoid a deadlock.

Note: the storm detection logic equals the implementation in
note_interrupt() which uses timestamps and counters stored in struct
irq_desc. Since this structure is private to the generic interrupt core
the TPM TIS core uses its own timestamps and counters. Furthermore the TPM
interrupt handler always returns IRQ_HANDLED to prevent the generic
interrupt core from processing the interrupt storm.

Cc: stable@vger.kernel.org # v6.4+
Fixes: e644b2f4 ("tpm, tpm_tis: Enable interrupt test")
Reported-by: default avatarkernel test robot <yujie.liu@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202305041325.ae8b0c43-yujie.liu@intel.com/


Suggested-by: default avatarLukas Wunner <lukas@wunner.de>
Signed-off-by: default avatarLino Sanfilippo <l.sanfilippo@kunbus.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 393f3623
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