From b154ce11ead925de6a94feb3b0317fafeefa0ebc Mon Sep 17 00:00:00 2001 From: Jerry Snitselaar Date: Thu, 15 Oct 2020 14:44:30 -0700 Subject: [PATCH] tpm_tis: Disable interrupts on ThinkPad T490s 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: Peter Huewe Cc: Jason Gunthorpe Cc: Hans de Goede Signed-off-by: Jerry Snitselaar Reviewed-by: James Bottomley Reviewed-by: Hans de Goede Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- 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 0b21496..4ed6e66 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -27,6 +27,7 @@ #include #include #include +#include #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; -- 2.7.4