diff options
| -rw-r--r-- | drivers/hwmon/dell-smm-hwmon.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index aef4f8317ae2..3f8b4e482b64 100644 --- a/drivers/hwmon/dell-smm-hwmon.c +++ b/drivers/hwmon/dell-smm-hwmon.c @@ -76,6 +76,7 @@ static uint i8k_fan_mult = I8K_FAN_MULT; static uint i8k_pwm_mult; static uint i8k_fan_max = I8K_FAN_HIGH; static bool disallow_fan_type_call; +static bool disallow_fan_support; #define I8K_HWMON_HAVE_TEMP1 (1 << 0) #define I8K_HWMON_HAVE_TEMP2 (1 << 1) @@ -242,6 +243,9 @@ static int i8k_get_fan_status(int fan) { struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, }; + if (disallow_fan_support) + return -EINVAL; + regs.ebx = fan & 0xff; return i8k_smm(®s) ? : regs.eax & 0xff; } @@ -253,6 +257,9 @@ static int i8k_get_fan_speed(int fan) { struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, }; + if (disallow_fan_support) + return -EINVAL; + regs.ebx = fan & 0xff; return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult; } @@ -264,7 +271,7 @@ static int _i8k_get_fan_type(int fan) { struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, }; - if (disallow_fan_type_call) + if (disallow_fan_support || disallow_fan_type_call) return -EINVAL; regs.ebx = fan & 0xff; @@ -289,6 +296,9 @@ static int i8k_get_fan_nominal_speed(int fan, int speed) { struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, }; + if (disallow_fan_support) + return -EINVAL; + regs.ebx = (fan & 0xff) | (speed << 8); return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult; } @@ -300,6 +310,9 @@ static int i8k_set_fan(int fan, int speed) { struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, }; + if (disallow_fan_support) + return -EINVAL; + speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed); regs.ebx = (fan & 0xff) | (speed << 8); @@ -772,6 +785,8 @@ static struct attribute *i8k_attrs[] = { static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr, int index) { + if (disallow_fan_support && index >= 8) + return 0; if (disallow_fan_type_call && (index == 9 || index == 12 || index == 15)) return 0; @@ -1039,6 +1054,23 @@ static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst }; /* + * On some machines all fan related SMM functions implemented by Dell BIOS + * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan + * support for affected blacklisted Dell machines stay disabled. + * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751 + */ +static struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initdata = { + { + .ident = "Dell Inspiron 7720", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"), + }, + }, + { } +}; + +/* * Probe for the presence of a supported laptop. */ static int __init i8k_probe(void) @@ -1060,6 +1092,12 @@ static int __init i8k_probe(void) i8k_get_dmi_data(DMI_BIOS_VERSION)); } + if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) { + pr_warn("broken Dell BIOS detected, disallow fan support\n"); + if (!force) + disallow_fan_support = true; + } + if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) { pr_warn("broken Dell BIOS detected, disallow fan type call\n"); if (!force) |