drm: Warn if plane/crtc/encoder/connector index exceeds our 32bit bitmasks
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Thu, 25 Jan 2018 13:30:20 +0000 (15:30 +0200)
committerVille Syrjälä <ville.syrjala@linux.intel.com>
Mon, 29 Jan 2018 16:46:53 +0000 (18:46 +0200)
commit2a8d3eac3d6e11638893ec3c4ba8bc5884db2ef9
tree25914b162b7e60b4fdf962589f8b54e4eec123f7
parent65f7fa3a3fcbdb67940a58ce24516d62aaec12b7
drm: Warn if plane/crtc/encoder/connector index exceeds our 32bit bitmasks

We use 32bit bitmasks to track planes/crtcs/encoders/connectors.
Naturally we can only do that if the index of those objects stays
below 32. Issue a warning whenever we exceed that limit, hopefully
prompting someone to fix the problem.

For connectors the issue is a bit more complicated as they can
be created/destroyed at runtime due to MST. So the problem is no
longer a purely theoretical programmer error. As the connector
indexes are allocated via ida, we can simply limit the maximum
value the ida is allowed to hand out. The error handling is already
in place.

v2: Return an error to the caller (Harry)
v3: Print a debug message so that we know what happened (Maarten)

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125133020.23845-1-ville.syrjala@linux.intel.com
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
drivers/gpu/drm/drm_connector.c
drivers/gpu/drm/drm_crtc.c
drivers/gpu/drm/drm_encoder.c
drivers/gpu/drm/drm_plane.c