Reading /sys/class/leds/<led>/trigger returns all available LED triggers. However, the size of this file is limited to PAGE_SIZE because of the limitation for sysfs attribute. Enabling LED CPU trigger on systems with thousands of CPUs easily hits PAGE_SIZE limit, and makes it impossible to see all available LED triggers and which trigger is currently activated. This patch converts /sys/class/leds/<led>/trigger to bin attribute and removes the PAGE_SIZE limitation. The first version of this seris provided the new api that follows the "one value per file" rule of sysfs. The second version dropped it because there have been a number of problems and it turns out that the new api should be submitted separately. * v3 - Remove "query" parameters from led_trigger_snprintf() and led_trigger_format() - Return -ENOMEM immediately if memory allocation fails - Drop Acked-by: tag due to a certain amount of changes * v2 - Update commit message - Drop patches for new api Akinobu Mita (1): leds: remove PAGE_SIZE limit of /sys/class/leds/<led>/trigger drivers/leds/led-class.c | 8 ++-- drivers/leds/led-triggers.c | 90 ++++++++++++++++++++++++++++++++++----------- drivers/leds/leds.h | 6 +++ include/linux/leds.h | 5 --- 4 files changed, 78 insertions(+), 31 deletions(-) Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Dan Murphy <dmurphy@xxxxxx> -- 2.7.4
