diff options
Diffstat (limited to 'drivers/acpi/ec.c')
| -rw-r--r-- | drivers/acpi/ec.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 6f4203716b53..7855bbf752b1 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -23,8 +23,10 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/list.h> +#include <linux/printk.h> #include <linux/spinlock.h> #include <linux/slab.h> +#include <linux/string.h> #include <linux/suspend.h> #include <linux/acpi.h> #include <linux/dmi.h> @@ -2031,6 +2033,25 @@ void __init acpi_ec_ecdt_probe(void) goto out; } + if (!strlen(ecdt_ptr->id)) { + /* + * The ECDT table on some MSI notebooks contains invalid data, together + * with an empty ID string (""). + * + * Section 5.2.15 of the ACPI specification requires the ID string to be + * a "fully qualified reference to the (...) embedded controller device", + * so this string always has to start with a backslash. + * + * However some ThinkBook machines have a ECDT table with a valid EC + * description but an invalid ID string ("_SB.PC00.LPCB.EC0"). + * + * Because of this we only check if the ID string is empty in order to + * avoid the obvious cases. + */ + pr_err(FW_BUG "Ignoring ECDT due to empty ID string\n"); + goto out; + } + ec = acpi_ec_alloc(); if (!ec) goto out; |