• Jesse Barnes's avatar
    drm/i915: preserve swizzle settings if necessary v4 · d9ceb816
    Jesse Barnes authored
    Some machines (like MBAs) might use a tiled framebuffer but not enable
    display swizzling at boot time.  We want to preserve that configuration
    if possible to prevent a boot time mode set.  On IVB+ it shouldn't
    affect performance anyway since the memory controller does internal
    swizzling anyway.
    
    For most other configs we'll be able to enable swizzling at boot time,
    since the initial framebuffer won't be tiled, thus we won't see any
    corruption when we enable it.
    
    v2: preserve swizzling if BIOS had it set (Daniel)
    v3: preserve swizzling only if we inherited a tiled framebuffer (Daniel)
        check display swizzle setting in detect_bit_6_swizzle (Daniel)
        use gen6 as cutoff point (Daniel)
    v4: fixup swizzle preserve again, had wrong init order (Daniel)
    Reported-by: default avatarKristian Høgsberg <hoegsberg@gmail.com>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    d9ceb816
i915_gem_tiling.c 16.8 KB