On Fri, Jun 10, 2022 at 01:08:42PM +0200, LinoSanfilippo@xxxxxx wrote:
> From: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
>
> According to the TPM Interface Specification (TIS) interrupts for
> "stsValid" and "commandReady" might not be supported.
>
> Take this into account and only wait for interrupts which are actually in
> use in wait_for_tpm_stat(). After that process all the remaining status
> changes by polling the status register.
>
> Signed-off-by: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
> ---
> drivers/char/tpm/tpm_tis_core.c | 46 ++++++++++++++++++++++++---------
> 1 file changed, 34 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 2f03fefa1706..028bec44362d 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -53,41 +53,63 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
> long rc;
> u8 status;
> bool canceled = false;
> + u8 active_irqs = 0;
Something like sts_mask would be a better name. Calling it
'active_irqs' is a bit confusing.
> + int ret = 0;
>
> /* check current status */
> status = chip->ops->status(chip);
> if ((status & mask) == mask)
> return 0;
>
> - stop = jiffies + timeout;
> + /* check what status changes can be handled by irqs */
> + if (priv->irqs_in_use & TPM_INTF_STS_VALID_INT)
> + active_irqs |= TPM_STS_VALID;
>
> - if (chip->flags & TPM_CHIP_FLAG_IRQ) {
> + if (priv->irqs_in_use & TPM_INTF_DATA_AVAIL_INT)
> + active_irqs |= TPM_STS_DATA_AVAIL;
> +
> + if (priv->irqs_in_use & TPM_INTF_CMD_READY_INT)
> + active_irqs |= TPM_STS_COMMAND_READY;
> +
> + active_irqs &= mask;
> +
> + stop = jiffies + timeout;
> + /* process status changes with irq support */
> + if (active_irqs) {
> + ret = -ETIME;
> again:
> timeout = stop - jiffies;
> if ((long)timeout <= 0)
> return -ETIME;
> rc = wait_event_interruptible_timeout(*queue,
> - wait_for_tpm_stat_cond(chip, mask, check_cancel,
> + wait_for_tpm_stat_cond(chip, active_irqs, check_cancel,
> &canceled),
> timeout);
> if (rc > 0) {
> if (canceled)
> return -ECANCELED;
> - return 0;
> + ret = 0;
> }
> if (rc == -ERESTARTSYS && freezing(current)) {
> clear_thread_flag(TIF_SIGPENDING);
> goto again;
> }
> - } else {
> - do {
> - usleep_range(priv->timeout_min,
> - priv->timeout_max);
> - status = chip->ops->status(chip);
> - if ((status & mask) == mask)
> - return 0;
> - } while (time_before(jiffies, stop));
> }
> +
> + if (ret)
> + return ret;
> +
> + mask &= ~active_irqs;
> + if (!mask) /* all done */
> + return 0;
> + /* process status changes without irq support */
> + do {
> + status = chip->ops->status(chip);
> + if ((status & mask) == mask)
> + return 0;
> + usleep_range(priv->timeout_min,
> + priv->timeout_max);
> + } while (time_before(jiffies, stop));
> return -ETIME;
> }
>
> --
> 2.36.1
>
BR, Jarkko
