drm/i915: Allow DBLSCAN user modes with eDP/LVDS/DSI

When encountering a connector with the scaling mode property both
intel and modesetting ddxs sometimes add tons of DBLSCAN modes
to the output's mode list. The idea presumably being that since the
output will be going through the panel fitter anyway we can pretend
to use any kind of mode.

Sadly that means we can't reject user modes with the DBLSCAN flag
until we know whether we're going to be using the panel's native
mode or the user mode directly. Doing otherwise means X clients using
xf86vidmode/xrandr will get a protocol error (and often self
terminate as a result) when the kernel refuses to use the requested
mode with the DBLSCAN flag.

To undo the regression we'll move the DBLSCAN checks into the
connector->mode_valid() and encoder->compute_config() hooks.

Cc: [email protected]
Cc: Vito Caputo <[email protected]>
Reported-by: Vito Caputo <[email protected]>
Fixes: e995ca0b8139 ("drm/i915: Provide a device level .mode_valid() hook")
References: https://lkml.org/lkml/2018/5/21/715
Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Maarten Lankhorst <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106804
Tested-by: Arkadiusz Miskiewicz <[email protected]>
(cherry picked from commit e4dd27aadd205417a2e9ea9902b698a0252ec3a0)
Signed-off-by: Jani Nikula <[email protected]>

0 files changed, 0 insertions, 0 deletions