On Wed, Jun 01, 2016 at 12:18:01PM -0700, Eric Anholt wrote:
It appears to have no callers.
Signed-off-by: Eric Anholt eric@anholt.net
drivers/gpu/drm/panel/panel-simple.c | 18 ------------------ include/drm/drm_panel.h | 4 ---- 2 files changed, 22 deletions(-)
Looks like I never replied to this, though I remember at least making up the reply in my head.
The reason why I'd like to keep this is that it's technically the right interface for display drivers to use. It was introduced in order to fix some of the short-comings of ->get_modes(), though it seems like there simply hasn't been a need so far for drivers to do this.
The problem with ->get_modes() is that it gives you a fixed mode for most panels. However, a mode that works on one display controller does not necessarily work on another (typical reasons could be extra limits imposed on porches by the display controller).
Timings are supposed to solve this by allowing the video timings to be specified in triplets of (minimum, maximum, typical) values for each of the parameters (much like the tables you see in panel datasheets) and make it possible for drivers to make up a valid mode from those ranges. This makes the panel more widely useful.
At least that's the theory, but, like I said, in practice nobody seems to be needing this currently.
Bottom line, I think we'll be needing this down the road eventually, so keeping it around will avoid unnecessary churn.
Thierry