• Will Deacon's avatar
    drivers: Remove explicit invocations of mmiowb() · fb24ea52
    Will Deacon authored
    mmiowb() is now implied by spin_unlock() on architectures that require
    it, so there is no reason to call it from driver code. This patch was
    generated using coccinelle:
    	- mmiowb();
    and invoked as:
    $ for d in drivers include/linux/qed sound; do \
    spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done
    NOTE: mmiowb() has only ever guaranteed ordering in conjunction with
    spin_unlock(). However, pairing each mmiowb() removal in this patch with
    the corresponding call to spin_unlock() is not at all trivial, so there
    is a small chance that this change may regress any drivers incorrectly
    relying on mmiowb() to order MMIO writes between CPUs using lock-free
    synchronisation. If you've ended up bisecting to this commit, you can
    reintroduce the mmiowb() calls using wmb() instead, which should restore
    the old behaviour on all architectures other than some esoteric ia64
    Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>