On Thu, Oct 15, 2020 at 02:44:30PM -0700, Jerry Snitselaar wrote: > There is a misconfiguration in the bios of the gpio pin used for the > interrupt in the T490s. When interrupts are enabled in the tpm_tis > driver code this results in an interrupt storm. This was initially > reported when we attempted to enable the interrupt code in the tpm_tis > driver, which previously wasn't setting a flag to enable it. Due to > the reports of the interrupt storm that code was reverted and we went back > to polling instead of using interrupts. Now that we know the T490s problem > is a firmware issue, add code to check if the system is a T490s and > disable interrupts if that is the case. This will allow us to enable > interrupts for everyone else. If the user has a fixed bios they can > force the enabling of interrupts with tpm_tis.interrupts=1 on the > kernel command line. > > Cc: [email protected] > Cc: Peter Huewe <[email protected]> > Cc: Jason Gunthorpe <[email protected]> > Cc: Hans de Goede <[email protected]> > Reviewed-by: James Bottomley <[email protected]> > Signed-off-by: Jerry Snitselaar <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]> I'll apply this and make it available in linux-next. /Jarkko > --- > drivers/char/tpm/tpm_tis.c | 29 +++++++++++++++++++++++++++-- > 1 file changed, 27 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c > index 0b214963539d..4ed6e660273a 100644 > --- a/drivers/char/tpm/tpm_tis.c > +++ b/drivers/char/tpm/tpm_tis.c > @@ -27,6 +27,7 @@ > #include <linux/of.h> > #include <linux/of_device.h> > #include <linux/kernel.h> > +#include <linux/dmi.h> > #include "tpm.h" > #include "tpm_tis_core.h" > > @@ -49,8 +50,8 @@ static inline struct tpm_tis_tcg_phy > *to_tpm_tis_tcg_phy(struct tpm_tis_data *da > return container_of(data, struct tpm_tis_tcg_phy, priv); > } > > -static bool interrupts = true; > -module_param(interrupts, bool, 0444); > +static int interrupts = -1; > +module_param(interrupts, int, 0444); > MODULE_PARM_DESC(interrupts, "Enable interrupts"); > > static bool itpm; > @@ -63,6 +64,28 @@ module_param(force, bool, 0444); > MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry"); > #endif > > +static int tpm_tis_disable_irq(const struct dmi_system_id *d) > +{ > + if (interrupts == -1) { > + pr_notice("tpm_tis: %s detected: disabling interrupts.\n", > d->ident); > + interrupts = 0; > + } > + > + return 0; > +} > + > +static const struct dmi_system_id tpm_tis_dmi_table[] = { > + { > + .callback = tpm_tis_disable_irq, > + .ident = "ThinkPad T490s", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), > + DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T490s"), > + }, > + }, > + {} > +}; > + > #if defined(CONFIG_PNP) && defined(CONFIG_ACPI) > static int has_hid(struct acpi_device *dev, const char *hid) > { > @@ -192,6 +215,8 @@ static int tpm_tis_init(struct device *dev, struct > tpm_info *tpm_info) > int irq = -1; > int rc; > > + dmi_check_system(tpm_tis_dmi_table); > + > rc = check_acpi_tpm2(dev); > if (rc) > return rc; > -- > 2.28.0 > >
