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    SubjectRe: [PATCH] tpm/tpm_i2c_infineon: ensure no ongoing commands on shutdown
    On Fri, Jan 13, 2017 at 04:09:54PM -0800, Andrey Pronin wrote:
    > Resetting TPM while processing a command may lead to issues
    > on the next boot. Ensure that we don't have any ongoing
    > commands, and that no further commands can be sent to the chip
    > by unregistering the device in the shutdown handler.
    > tpm_chip_unregister() waits for the completion of an ongoing
    > command, if any, and then clears out chip->ops and unregisters
    > sysfs entities.

    Unregistering in a shutdown handler seems very strange, it also waits
    for userspace things, so I wonder if it could be problematic?

    Maybe just use

    down_write(&chip->ops_sem);
    chip->ops = NULL;
    up_write(&chip->ops_sem);

    In the shutdown handler?

    Jason

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