• David Brownell's avatar
    dma_free_coherent() needs irqs enabled (sigh) · aa24886e
    David Brownell authored
    
    
    On at least ARM (and I'm told MIPS too) dma_free_coherent() has a newish
    call context requirement: unlike its dma_alloc_coherent() sibling, it may
    not be called with IRQs disabled.  (This was new behavior on ARM as of late
    2005, caused by ARM SMP updates.) This little surprise can be annoyingly
    driver-visible.
    
    Since it looks like that restriction won't be removed, this patch changes
    the definition of the API to include that requirement.  Also, to help catch
    nonportable drivers, it updates the x86 and swiotlb versions to include the
    relevant warnings.  (I already observed that it trips on the
    bus_reset_tasklet of the new firewire_ohci driver.)
    
    Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
    Cc: David Miller <davem@davemloft.net>
    Acked-by: default avatarRussell King <rmk@arm.linux.org.uk>
    Cc: Andi Kleen <ak@suse.de>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    aa24886e