diff options
Diffstat (limited to 'include/linux/rfkill.h')
| -rw-r--r-- | include/linux/rfkill.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h index 278777fa8a3..10202903141 100644 --- a/include/linux/rfkill.h +++ b/include/linux/rfkill.h @@ -82,6 +82,20 @@ struct rfkill_event { __u8 soft, hard; } __packed; +/* + * We are planning to be backward and forward compatible with changes + * to the event struct, by adding new, optional, members at the end. + * When reading an event (whether the kernel from userspace or vice + * versa) we need to accept anything that's at least as large as the + * version 1 event size, but might be able to accept other sizes in + * the future. + * + * One exception is the kernel -- we already have two event sizes in + * that we've made the 'hard' member optional since our only option + * is to ignore it anyway. + */ +#define RFKILL_EVENT_SIZE_V1 8 + /* ioctl for turning off rfkill-input (if present) */ #define RFKILL_IOC_MAGIC 'R' #define RFKILL_IOC_NOINPUT 1 |