Thank you Jarkko. I'll do that. Jim
On Thu, May 21, 2026 at 4:48 PM Jarkko Sakkinen <[email protected]> wrote: > > On Mon, May 18, 2026 at 11:09:26PM -0700, Jim Broadus wrote: > > Some TPMs fail to grant locality when requested immediately after being > > relinquished. In this case, the TPM_ACCESS_REQUEST_USE bit of the > > TPM_ACCESS register is cleared immediately without setting > > TPM_ACCESS_ACTIVE_LOCALITY. > > > > This issue can be seen at boot since tpm_chip_start, called right > > after locality is relinquished, fails. This causes the probe to fail: > > > > tpm_tis MSFT0101:00: probe with driver tpm_tis failed with error -1 > > > > This occurs on some older Dell Latitudes and maybe others. To work > > around this, add a "settle" boolean param to tpm_tis. When this is > > enabled, a delay is added after locality is relinquished. > > > > Signed-off-by: Jim Broadus <[email protected]> > > It would be better idea first to replace priv->manufacturer_id with > priv->did_vid, and make necessary changes to sites where it is used. > > Then in the if-statement compare DID/VID of the device to priv->did_vid > and apply quirk only if it matches. > > > --- > > Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ > > drivers/char/tpm/tpm_tis.c | 7 +++++++ > > drivers/char/tpm/tpm_tis_core.c | 3 +++ > > drivers/char/tpm/tpm_tis_core.h | 1 + > > 4 files changed, 18 insertions(+) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > b/Documentation/admin-guide/kernel-parameters.txt > > index 4d0f545fb3ec..5b7111033fbb 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -7651,6 +7651,13 @@ Kernel parameters > > defined by Trusted Computing Group (TCG) see > > > > https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/ > > > > + tpm_tis.settle= [HW,TPM] > > + Format: <bool> > > + When enabled, this adds a delay after locality is > > + relinquished. Some TPMs will fail to grant locality if > > + requested immediately after being relinquished. This > > + causes the probe to fail. > > + > > tp_printk [FTRACE] > > Have the tracepoints sent to printk as well as the > > tracing ring buffer. This is useful for early boot up > > diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c > > index 9aa230a63616..8ac0ea78570e 100644 > > --- a/drivers/char/tpm/tpm_tis.c > > +++ b/drivers/char/tpm/tpm_tis.c > > @@ -101,6 +101,10 @@ module_param(force, bool, 0444); > > MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry"); > > #endif > > > > +static bool settle; > > +module_param(settle, bool, 0444); > > +MODULE_PARM_DESC(settle, "Add settle time after relinquish"); > > + > > #if defined(CONFIG_PNP) && defined(CONFIG_ACPI) > > static int has_hid(struct acpi_device *dev, const char *hid) > > { > > @@ -242,6 +246,9 @@ static int tpm_tis_init(struct device *dev, struct > > tpm_info *tpm_info) > > if (itpm || is_itpm(ACPI_COMPANION(dev))) > > set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags); > > > > + if (settle) > > + set_bit(TPM_TIS_SETTLE_AFTER_RELINQUISH, &phy->priv.flags); > > + > > return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg, > > ACPI_HANDLE(dev)); > > } > > diff --git a/drivers/char/tpm/tpm_tis_core.c > > b/drivers/char/tpm/tpm_tis_core.c > > index 21d79ad3b164..68be26fa5817 100644 > > --- a/drivers/char/tpm/tpm_tis_core.c > > +++ b/drivers/char/tpm/tpm_tis_core.c > > @@ -184,6 +184,9 @@ static int tpm_tis_relinquish_locality(struct tpm_chip > > *chip, int l) > > __tpm_tis_relinquish_locality(priv, l); > > mutex_unlock(&priv->locality_count_mutex); > > > > + if (test_bit(TPM_TIS_SETTLE_AFTER_RELINQUISH, &priv->flags)) > > + tpm_msleep(TPM_TIMEOUT); > > + > > return 0; > > } > > > > diff --git a/drivers/char/tpm/tpm_tis_core.h > > b/drivers/char/tpm/tpm_tis_core.h > > index 6c3aa480396b..413cac5e0f31 100644 > > --- a/drivers/char/tpm/tpm_tis_core.h > > +++ b/drivers/char/tpm/tpm_tis_core.h > > @@ -90,6 +90,7 @@ enum tpm_tis_flags { > > TPM_TIS_DEFAULT_CANCELLATION = 2, > > TPM_TIS_IRQ_TESTED = 3, > > TPM_TIS_STATUS_VALID_RETRY = 4, > > + TPM_TIS_SETTLE_AFTER_RELINQUISH = 5, > > }; > > > > struct tpm_tis_data { > > -- > > 2.54.0 > > > > BR, Jarkko
