Re: [PATCH] leds: remove PAGE_SIZE limit of /sys/class/leds/<led>/trigger

From: Jacek Anaszewski
Date: Thu Sep 12 2019 - 13:16:04 EST


Hi Akinobu,

Please bump patch version each time you send an update
of the patch with the same subject.

Best regards,
Jacek Anaszewski

On 9/12/19 4:39 PM, Akinobu Mita wrote:
> 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.
>
> We work around it here by converting /sys/class/leds/<led>/trigger to
> binary attribute, which is not limited by length. This is _not_ good
> design, do not copy it.