diff options
| -rw-r--r-- | drivers/acpi/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/acpi/ec_sys.c | 31 |
2 files changed, 32 insertions, 10 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f7226d1bc80..08e0140920e 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -106,14 +106,19 @@ config ACPI_SYSFS_POWER config ACPI_EC_DEBUGFS tristate "EC read/write access through /sys/kernel/debug/ec" - default y + default n help Say N to disable Embedded Controller /sys/kernel/debug interface + Be aware that using this interface can confuse your Embedded + Controller in a way that a normal reboot is not enough. You then + have to power of your system, and remove the laptop battery for + some seconds. An Embedded Controller typically is available on laptops and reads sensor values like battery state and temperature. - The kernel access the EC through ACPI parsed code provided by BIOS - tables. + The kernel accesses the EC through ACPI parsed code provided by BIOS + tables. This option allows to access the EC directly without ACPI + code being involved. Thus this option is a debug option that helps to write ACPI drivers and can be used to identify ACPI code or EC firmware bugs. diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c index 3ef978185c7..0e869b3f81c 100644 --- a/drivers/acpi/ec_sys.c +++ b/drivers/acpi/ec_sys.c @@ -17,6 +17,11 @@ MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>"); MODULE_DESCRIPTION("ACPI EC sysfs access driver"); MODULE_LICENSE("GPL"); +static bool write_support; +module_param(write_support, bool, 0644); +MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may " + "be needed."); + #define EC_SPACE_SIZE 256 struct sysdev_class acpi_ec_sysdev_class = { @@ -102,6 +107,8 @@ int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) { struct dentry *dev_dir; char name[64]; + mode_t mode = 0400; + if (ec_device_count == 0) { acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); if (!acpi_ec_debugfs_dir) @@ -111,17 +118,27 @@ int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) sprintf(name, "ec%u", ec_device_count); dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); if (!dev_dir) { - if (ec_device_count == 0) - debugfs_remove_recursive(acpi_ec_debugfs_dir); - /* TBD: Proper cleanup for multiple ECs */ + if (ec_device_count != 0) + goto error; return -ENOMEM; } - debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe); - debugfs_create_bool("use_global_lock", 0444, dev_dir, - (u32 *)&first_ec->global_lock); - debugfs_create_file("io", 0666, dev_dir, ec, &acpi_ec_io_ops); + if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) + goto error; + if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, + (u32 *)&first_ec->global_lock)) + goto error; + + if (write_support) + mode = 0600; + if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops)) + goto error; + return 0; + +error: + debugfs_remove_recursive(acpi_ec_debugfs_dir); + return -ENOMEM; } static int __init acpi_ec_sys_init(void) |