dmaengine: rcar-dmac: Disable channel 0 when using IOMMU
dmaengine: rcar-dmac: Disable channel 0 when using IOMMU

A still unconfirmed hardware bug prevents the IPMMU microTLB 0 to be
flushed correctly, resulting in memory corruption. DMAC 0 channel 0 is
connected to microTLB 0 on currently supported platforms, so we can't
use it with the IPMMU. As the IOMMU API operates at the device level we
can't disable it selectively, so ignore channel 0 for now if the device
is part of an IOMMU group.

Signed-off-by: Laurent Pinchart <ae960578cc5eca7b9b1dbc37d9caa6cb634f35e0@ideasonboard.com>
Acked-by: Geert Uytterhoeven <a1ff81395f7e6bf5b509fe9aab06bf3419493e1d@glider.be>
Signed-off-by: Vinod Koul <5cf69c63beb17bf38d63aa0e923ee8256af0e205@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs