Hi Lukasz,
On Sat, Jan 23, 2021 at 02:42:47AM +0100, Lukasz Majczak wrote:
> There is a missing call to start_tpm_chip before the call to
> the tpm_get_timeouts() and tpm_tis_probe_irq_single(). As the current
> approach maight work for tpm2, it fails for tpm1.x - in that case
> call to tpm_get_timeouts() or tpm_tis_probe_irq_single() tries to
> transmit TPM commands on a disabled chip what what doesn't succeed
s/what what/what/
> and in turn causes tpm_tis_core_init() to fail.
> Tested on Samsung Chromebook Pro (Caroline).
>
> Signed-off-by: Lukasz Majczak <lma@xxxxxxxxxxxx>
> ---
> drivers/char/tpm/tpm_tis_core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 92c51c6cfd1b..ff0e5fe46a9d 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -1063,12 +1063,16 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> init_waitqueue_head(&priv->read_queue);
> init_waitqueue_head(&priv->int_queue);
> if (irq != -1) {
> + rc = tpm_chip_start(chip);
Unless I am missing something, the underlying problem seems to be
the calls to tpm1_getcap(). From other code calling this function,
it looks like it may only require tpm_clk_enable() to work.
With that in mind, would it possibly be better to call tpm_clk_enable()
and tpm_clk_disable() around the calls to tpm1_getcap(), ie in
tpm1_get_timeouts() and in tpm_tis_gen_interrupt() ?
This would avoid the unnecessary calls to tpm_chip_start() and
tpm_chip_stop() for tpm2 chips.
Thanks,
Guenter
> + if (rc)
> + goto out_err;
> /* Before doing irq testing issue a command to the TPM in polling mode
> * to make sure it works. May as well use that command to set the
> * proper timeouts for the driver.
> */
> if (tpm_get_timeouts(chip)) {
> dev_err(dev, "Could not get TPM timeouts and durations\n");
> + tpm_chip_stop(chip);
> rc = -ENODEV;
> goto out_err;
> }
> @@ -1085,6 +1089,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> } else {
> tpm_tis_probe_irq(chip, intmask);
> }
> + tpm_chip_stop(chip);
> }
>
> rc = tpm_chip_register(chip);
