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    ARM: dts: STi: stih407-family: Disable reserved-memory co-processor nodes · 0e289e53
    Lee Jones authored
    This patch fixes a non-booting issue in Mainline.
    
    When booting with a compressed kernel, we need to be careful how we
    populate memory close to DDR start.  AUTO_ZRELADDR is enabled by default
    in multi-arch enabled configurations, which place some restrictions on
    where the kernel is placed and where it will be uncompressed to on boot.
    
    AUTO_ZRELADDR takes the decompressor code's start address and masks out
    the bottom 28 bits to obtain an address to uncompress the kernel to
    (thus a load address of 0x42000000 means that the kernel will be
    uncompressed to 0x40000000 i.e. DDR START on this platform).
    
    Even changing the load address to after the co-processor's shared memory
    won't render a booting platform, since the AUTO_ZRELADDR algorithm still
    ensures the kernel is uncompressed into memory shared with the first
    co-processor (0x40000000).
    
    Another option would be to move loading to 0x4A000000, since this will
    mean the decompressor will decompress the kernel to 0x48000000. However,
    this would mean a large chunk (0x44000000 => 0x48000000 (64MB)) of
    memory would essentially be wasted for no good reason.
    
    Until we can work with ST to find a suitable memory location to
    relocate co-processor shared memory, let's disable the shared memory
    nodes.  This will ensure a working platform in the mean time.
    
    NB: The more observant of you will notice that we're leaving the DMU
    shared memory node enabled; this is because a) it is the only one in
    active use at the time of this writing and b) it is not affected by
    the current default behaviour which is causing issues.
    
    Fixes: fe135c63
    
     (ARM: dts: STiH407: Move over to using the 'reserved-memory' API for obtaining DMA memory)
    Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
    Reviewed-by Peter Griffin <peter.griffin@linaro.org>
    Signed-off-by: default avatarMaxime Coquelin <maxime.coquelin@st.com>
    Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
    0e289e53