On Fr, 2017-04-21 at 12:25 +0300, Ville Syrjälä wrote: > On Fri, Apr 21, 2017 at 09:58:24AM +0200, Gerd Hoffmann wrote: > > While working on graphics support for virtual machines on ppc64 (which > > exists in both little and big endian variants) I've figured the comments > > for various drm fourcc formats in the header file don't match reality. > > > > Comments says the RGB formats are little endian, but in practice they > > are native endian. Look at the drm_mode_legacy_fb_format() helper. It > > maps -- for example -- bpp/depth 32/24 to DRM_FORMAT_XRGB8888, no matter > > whenever the machine is little endian or big endian. The users of this > > function (fbdev emulation, DRM_IOCTL_MODE_ADDFB) expect the framebuffer > > is native endian, not little endian. Most userspace also operates on > > native endian only. > > I'm not a fan of "native". Native to what? "CPU" or "host" is what I'd > call it. native == whatever the cpu is using. I personally find "native" more intuitive, but at the end of the day I don't mind much. If people prefer "host" over "native" I'll change it. > And what about the mxied endian case? Are you just going to pretend it > doesn't exist or what? What exactly do you mean with "mixed endian"? The powerpc case, where kernel + userspace can run in either big or little endian mode? Or something else? cheers, Gerd
