From 500de3dd46ac9f9ae9d124634c68907b7d50d2cb Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Thu, 29 Jul 2010 22:30:24 +0200 Subject: acpi ec_sys: Be more cautious about ec write access - Set Kconfig option default n - Only allow root to read/write io file (sever bug!) - Introduce write support module param -> default off - Properly clean up if any debugfs files cannot be created Signed-off-by: Thomas Renninger CC: mjg59@srcf.ucam.org CC: platform-driver-x86@vger.kernel.org CC: linux-acpi@vger.kernel.org CC: astarikovskiy@suse.de Signed-off-by: Matthew Garrett --- drivers/acpi/Kconfig | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/acpi/Kconfig') diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f7226d1bc80e..08e0140920e1 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. -- cgit v1.2.2