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-rw-r--r--drivers/hwmon/dell-smm-hwmon.c80
1 files changed, 57 insertions, 23 deletions
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index c43318d34..a9356a3de 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -66,11 +66,13 @@
static DEFINE_MUTEX(i8k_mutex);
static char bios_version[4];
+static char bios_machineid[16];
static struct device *i8k_hwmon_dev;
static u32 i8k_hwmon_flags;
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;
#define I8K_HWMON_HAVE_TEMP1 (1 << 0)
#define I8K_HWMON_HAVE_TEMP2 (1 << 1)
@@ -94,13 +96,13 @@ module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
#if IS_ENABLED(CONFIG_I8K)
-static bool restricted;
+static bool restricted = true;
module_param(restricted, bool, 0);
-MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
+MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
static bool power_status;
module_param(power_status, bool, 0600);
-MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
+MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
#endif
static uint fan_mult;
@@ -235,14 +237,28 @@ static int i8k_get_fan_speed(int fan)
/*
* Read the fan type.
*/
-static int i8k_get_fan_type(int fan)
+static int _i8k_get_fan_type(int fan)
{
struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
+ if (disallow_fan_type_call)
+ return -EINVAL;
+
regs.ebx = fan & 0xff;
return i8k_smm(&regs) ? : regs.eax & 0xff;
}
+static int i8k_get_fan_type(int fan)
+{
+ /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
+ static int types[2] = { INT_MIN, INT_MIN };
+
+ if (types[fan] == INT_MIN)
+ types[fan] = _i8k_get_fan_type(fan);
+
+ return types[fan];
+}
+
/*
* Read the fan nominal rpm for specific fan speed.
*/
@@ -392,9 +408,11 @@ i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
break;
case I8K_MACHINE_ID:
- memset(buff, 0, 16);
- strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
- sizeof(buff));
+ if (restricted && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ memset(buff, 0, sizeof(buff));
+ strlcpy(buff, bios_machineid, sizeof(buff));
break;
case I8K_FN_STATUS:
@@ -511,7 +529,7 @@ static int i8k_proc_show(struct seq_file *seq, void *offset)
seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
I8K_PROC_FMT,
bios_version,
- i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
+ (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
cpu_temp,
left_fan, right_fan, left_speed, right_speed,
ac_power, fn_key);
@@ -718,6 +736,9 @@ static struct attribute *i8k_attrs[] = {
static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
int index)
{
+ if (disallow_fan_type_call &&
+ (index == 9 || index == 12))
+ return 0;
if (index >= 0 && index <= 1 &&
!(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
return 0;
@@ -767,13 +788,17 @@ static int __init i8k_init_hwmon(void)
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
- /* First fan attributes, if fan type is OK */
- err = i8k_get_fan_type(0);
+ /* First fan attributes, if fan status or type is OK */
+ err = i8k_get_fan_status(0);
+ if (err < 0)
+ err = i8k_get_fan_type(0);
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
- /* Second fan attributes, if fan type is OK */
- err = i8k_get_fan_type(1);
+ /* Second fan attributes, if fan status or type is OK */
+ err = i8k_get_fan_status(1);
+ if (err < 0)
+ err = i8k_get_fan_type(1);
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
@@ -929,12 +954,14 @@ static struct dmi_system_id i8k_dmi_table[] __initdata = {
MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
-static struct dmi_system_id i8k_blacklist_dmi_table[] __initdata = {
+/*
+ * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
+ * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
+ * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
+ * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
+ */
+static struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initdata = {
{
- /*
- * CPU fan speed going up and down on Dell Studio XPS 8000
- * for unknown reasons.
- */
.ident = "Dell Studio XPS 8000",
.matches = {
DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
@@ -942,16 +969,19 @@ static struct dmi_system_id i8k_blacklist_dmi_table[] __initdata = {
},
},
{
- /*
- * CPU fan speed going up and down on Dell Studio XPS 8100
- * for unknown reasons.
- */
.ident = "Dell Studio XPS 8100",
.matches = {
DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
},
},
+ {
+ .ident = "Dell Inspiron 580",
+ .matches = {
+ DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
+ },
+ },
{ }
};
@@ -966,8 +996,7 @@ static int __init i8k_probe(void)
/*
* Get DMI information
*/
- if (!dmi_check_system(i8k_dmi_table) ||
- dmi_check_system(i8k_blacklist_dmi_table)) {
+ if (!dmi_check_system(i8k_dmi_table)) {
if (!ignore_dmi && !force)
return -ENODEV;
@@ -978,8 +1007,13 @@ static int __init i8k_probe(void)
i8k_get_dmi_data(DMI_BIOS_VERSION));
}
+ if (dmi_check_system(i8k_blacklist_fan_type_dmi_table))
+ disallow_fan_type_call = true;
+
strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
sizeof(bios_version));
+ strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
+ sizeof(bios_machineid));
/*
* Get SMM Dell signature
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-16 11:26:43 +0000