• Lyude Paul's avatar
    drm/nouveau/kms/nv140-: Use hard-coded wndws or core channel for CRC channel · 57cbdbe6
    Lyude Paul authored
    Originally it was assumed based on Nvidia's open-gpu-docs and testing that
    NVDisplay required that at least one wndw which belongs to a given head to
    be used as the controlling channel
    (NVC37D_HEAD_SET_CRC_CONTROL_CONTROLLING_CHANNEL) in order for CRC capture
    to function. While this is the case on Volta, Turing actually adds the
    ability to instead use the core channel as the controlling channel. For
    Turing this is quite useful, as it means that we can always default to the
    core channel as the controlling channel and we don't need to be concerned
    about ensuring we have at least one wndw channel owned by a head with CRC
    output enabled. While Volta lacks this ability, Volta conveniently also
    lacks flexible wndw mapping - meaning that we can always rely on each head
    having four wndw channels mapped to it regardless of the atomic state.
    
    So, simply use the hard-coded wndw mappings we're guaranteed to have on
    Volta as the controlling channel, and use the core channel as the
    controlling channel for Turing+. As a result this also renders the plane
    ownership logic in nv50_crc_atomic_check() unnessecary, which gives us one
    less thing to implement when we get support for flexible wndw mapping. We
    also can entirely drop the wndw parameter from our set_src callbacks, and
    the atomic state.
    
    v2 (Karol): put prackets around complex macro definition
                removed spaces before :32 in structs
    
    Cc: Martin Peres <martin.peres@free.fr>
    Cc: Jeremy Cline <jcline@redhat.com>
    Cc: Simon Ser <contact@emersion.fr>
    Signed-off-by: default avatarLyude Paul <lyude@redhat.com>
    Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
    Reviewed-by: default avatarKarol Herbst <kherbst@redhat.com>
    Signed-off-by: default avatarKarol Herbst <kherbst@redhat.com>
    Link: https://gitlab.freedesktop.org/drm/nouveau/-/merge_requests/10
    57cbdbe6
clc57d.h 30.7 KB