On Tue, Jan 09, 2018 at 03:28:23PM +0000, Chris Wilson wrote:
Quoting Ville Syrjälä (2018-01-09 15:19:06)
On Sun, Dec 31, 2017 at 01:03:39AM -0500, Ilia Mirkin wrote:
NVIDIA hardware, prior to Kepler, only supports XBGR2101010. However drmAddFB with depth = 30 will use the mapping in drm_mode_legacy_fb_format and pick the XRGB version of the format.
One solution is to tell userspace "stop using addfb, move to addfb2". However I'm hoping that there's some sort of semi-clean way of dealing with such driver eccentricities without resorting to changing userspace.
Can the ioctl be handled in the driver perhaps? Or would it be reasonable to add a callback in drm_driver?
I don't think there's any sane way to allow the driver to remap these. How would generic userspace know which component order the driver actually picked?
With getfb? Wait, I'll get my coat.
debugfs would dump the actual pixel format, at least in 4.16 :-) -Daniel