On 1/28/15 1:38 AM, Elizabeth Myers wrote: > Hello, > > I want to add backlight support to the i915 driver in FreeBSD. It seems > that two magic addresses are read and wrote from to change the backlight > itself. It supports rather fine-level granularity all the way down to > zero. Right now I use a hacked-up userland program that reads > from/writes to these addresses, which is far from an ideal solution. > > I am interested in this because the acpi_video(4) driver does not > support my backlight on my Dell Inspiron 15 3521 (not terribly > suprising, on Linux I needed a special Dell-specific driver, and I'm not > sure even that really used ACPI, I never really checked). > > My questions are really twofold: > > 1) How can this be exposed appropriately? I would prefer this be exposed > generally so upower could grok it. As far as I can tell upower uses > hw.acpi.video.lcd0 to control backlight. I am not sure that upower is > doing the "right" thing here, though. > 2) Where would the code go for this? The dri2 driver seems the most > "logical" place, but maybe it belongs in X and exposed via a program? Or > something else entirely that I'm not thinking of? > > I have experience developing PCI drivers and doing other PCI related > doodads, and some kernel development experience, as well as general C > experience, but I'm not by any means an expert on the matter.
Humm. If the code is going to live in the drm driver, then I would start with hanging a sysctl off of the drm device itself. (Each new-bus device_t has a sysctl ctx you can get to hang new nodes off of the device's node.) -- John Baldwin _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"