• Daniel Vetter's avatar
    drm/i915: fix tiling limits for i915 class hw v2 · c36a2a6d
    Daniel Vetter authored
    Current code is definitely crap: Largest pitch allowed spills into
    the TILING_Y bit of the fence registers ... :(
    
    I've rewritten the limits check under the assumption that 3rd gen hw
    has a 3d pitch limit of 8kb (like 2nd gen). This is supported by an
    otherwise totally misleading XXX comment.
    
    This bug mostly resulted in tiling-corrupted pixmaps because the kernel
    allowed too wide buffers to be tiled. Bug brought to the light by the
    xf86-video-intel 2.11 release because that unconditionally enabled
    tiling for pixmaps, relying on the kernel to check things. Tiling for
    the framebuffer was not affected because the ddx does some additional
    checks there ensure the buffer is within hw-limits.
    
    v2: Instead of computing the value that would be written into the
    hw fence registers and then checking the limits simply check whether
    the stride is above the 8kb limit. To better document the hw, add
    some WARN_ONs in i915_write_fence_reg like I've done for the i830
    case (using the right limits).
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=27449Tested-by: default avatarAlexander Lam <lambchop468@gmail.com>
    Cc: stable@kernel.org
    Signed-off-by: default avatarEric Anholt <eric@anholt.net>
    c36a2a6d
i915_reg.h 91.3 KB