[libata] sata_mv: Enable use of (basic) DMA for ATAPI on GEN_IIE chips
This also gets rid of any need for mv_mode_filter().
Using basic DMA on GEN_IIE requires setting an undocumented
bit in an undocumented register. For safety, we clear that
bit again when switching back to EDMA mode.
To avoid a performance penalty when switching modes,
we cache the register in port_priv, as already done for other regs.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
1 file changed