On 11/24/2016 10:15 AM, Pali Rohár wrote:
On Wednesday 23 November 2016 12:01:02 Jacek Anaszewski wrote:I would also appreciate your opinion on the other solution to the problem of notifying brightness changes originating from hardware, i.e. hw_brightness_change{_ro} file, that would support POLLPRI events, and reading brightness.Another idea: If no trigger is active then led subsystem will invoke POLLPRI on "brightness" sysfs file. And if there is active trigger then only trigger code could invoke POLLPRI on "brightness" file. This could solve problem with high CPU load and power usage when e.g. cpu trigger is active (and cpu trigger will not implement any POLLPRI). Do not know if this is really enough for your situation, it is just and another idea.
This way we would be losing POLLPRI events when trigger is active, whereas it would be useful to have ones in some use cases.
But first please update documentation in ABI/testing to match current situation. That is really needed.
I suppose that you're thinking about behaviour on brightness file reading? Is there anything else you'd like to have clarified in the doc? -- Best regards, Jacek Anaszewski -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
