• Jani Nikula's avatar
    drm/i915/bios: handle MIPI Sequence Block v3+ gracefully · bacda5a9
    Jani Nikula authored
    commit cd67d226 upstream.
    
    The VBT MIPI Sequence Block version 3 has forward incompatible changes:
    
    First, the block size in the header has been specified reserved, and the
    actual size is a separate 32-bit value within the block. The current
    find_section() function to will only look at the size in the block
    header, and, depending on what's in that now reserved size field,
    continue looking for other sections in the wrong place.
    
    Fix this by taking the new block size field into account. This will
    ensure that the lookups for other sections will work properly, as long
    as the new 32-bit size does not go beyond the opregion VBT mailbox size.
    
    Second, the contents of the block have been completely
    changed. Gracefully refuse parsing the yet unknown data version.
    
    Cc: Deepak M <m.deepak@intel.com>
    Reviewed-by: default avatarDeepak M <m.deepak@intel.com>
    Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
    [ luis: backported to 3.16: adjusted context ]
    Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
    bacda5a9
intel_bios.c 35.2 KB