On Mon, 2009-07-13 at 21:41 +0100, Matthew Garrett wrote: > Certain hardware will send us events when the backlight brightness > changes. Add a function to update the value in the core, and > additionally send a uevent so that userspace can pop up appropriate > UI. The uevents are flagged depending on whether the update originated > in the kernel or from userspace, making it easier to only display UI > at the appropriate time. This looks good and I like the idea. My main concern is that we don't start getting bug reports of 'missing' events and have clearly defined expectations of when we see what kind of events. For example, should an event be emitted when low battery causes the backlight to be limited? How about console blanking events turning off the backlight? Are there any other occasions we should be emitting change events and do we need to audit other drivers? I did look to see if we could integrate this more into the backlight core but that doesn't look to be possible unfortunately, at least not without changing the drivers which these patches start. Also, are "userspace" and "kernel" as meaningful as they could be? Would "sysfs" and "hwkeys" make more sense and allow for other future hardware differences? Perhaps someone will tie the backlight to an ambient light sensor for example... Cheers, Richard -- Richard Purdie Intel Open Source Technology Centre -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
