On Sat, 2021-10-02 at 11:14 +0200, Hans de Goede wrote: > Hi Lyude, > > On 10/2/21 12:53 AM, Lyude Paul wrote: > > When I originally moved all of the VESA backlight code in i915 into DRM > > helpers, one of the things I didn't have the hardware or time for > > testing was machines that used a combination of PWM and DPCD in order to > > control their backlights. This has since then caused some breakages and > > resulted in us disabling DPCD backlight support on such machines. This > > works fine, unless you have a machine that actually needs this > > functionality for backlight controls to work at all. Additionally, we > > will need to support PWM for when we start adding support for VESA's > > product (as in the product of multiplication) control mode for better > > brightness ranges. > > > > So - let's finally finish up implementing basic support for these types > > of backlights to solve these problems in our DP helpers, along with > > implementing support for this in i915. And since digging into this issue > > solved the last questions we really had about probing backlights in i915 > > for the most part, let's update some of the comments around that as > > well! > > Backlight control is a topic which I'm reasonably familiar with, > do you want me to review this series for you ? Possibly, although I definitely want to make sure that someone from Intel gets a chance to review this as well. I'm more curious if you might happen to have any systems that would be able to test this. > > Regards, > > Hans > > > > > > > Changes: > > * Fixup docs > > * Add patch to stop us from breaking nouveau > > > > Lyude Paul (4): > > drm/i915: Add support for panels with VESA backlights with PWM > > enable/disable > > drm/nouveau/kms/nv50-: Explicitly check DPCD backlights for aux > > enable/brightness > > drm/dp, drm/i915: Add support for VESA backlights using PWM for > > brightness control > > drm/i915: Clarify probing order in intel_dp_aux_init_backlight_funcs() > > > > drivers/gpu/drm/drm_dp_helper.c | 75 +++++++++++------ > > .../drm/i915/display/intel_dp_aux_backlight.c | 80 ++++++++++++++----- > > drivers/gpu/drm/nouveau/nouveau_backlight.c | 5 +- > > include/drm/drm_dp_helper.h | 7 +- > > 4 files changed, 122 insertions(+), 45 deletions(-) > > > -- Cheers, Lyude Paul (she/her) Software Engineer at Red Hat