• Ankit Nautiyal's avatar
    drm: Add DRM client cap for aspect-ratio · 7595bda2
    Ankit Nautiyal authored
    To enable aspect-ratio support in DRM, blindly exposing the aspect
    ratio information along with mode, can break things in existing
    non-atomic user-spaces which have no intention or support to use this
    aspect ratio information.
    
    To avoid this, a new drm client cap is required to enable a non-atomic
    user-space to advertise if it supports modes with aspect-ratio. Based
    on this cap value, the kernel will take a call on exposing the aspect
    ratio info in modes or not.
    
    This patch adds the client cap for aspect-ratio.
    
    Since no atomic-userspaces blow up on receiving aspect-ratio
    information, the client cap for aspect-ratio is always enabled
    for atomic clients.
    
    Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
    Cc: Shashank Sharma <shashank.sharma@intel.com>
    Signed-off-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
    
    V3: rebase
    V4: As suggested by Marteen Lankhorst modified the commit message
        explaining the need to use the DRM cap for aspect-ratio. Also,
        tweaked the comment lines in the code for better understanding and
        clarity, as recommended by Shashank Sharma.
    V5: rebase
    V6: rebase
    V7: rebase
    V8: rebase
    V9: rebase
    V10: rebase
    V11: rebase
    V12: As suggested by Daniel Vetter and Ville Syrjala,
         always enable aspect-ratio client cap for atomic userspaces,
         if no atomic userspace breaks on aspect-ratio bits.
    V13: rebase
    V14: rebase
    Reviewed-by: default avatarShashank Sharma <shashank.sharma@intel.com>
    Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/1525777785-9740-7-git-send-email-ankit.k.nautiyal@intel.com
    7595bda2
drm.h 30.3 KB