[libata] sata_mv: Enable use of (basic) DMA for ATAPI on GEN_IIE chips
commitc01e8a23128c746f23088db836bd4c820f3eb0b4
authorMark Lord <mlord@pobox.com>
Wed, 25 Feb 2009 20:14:48 +0000 (25 15:14 -0500)
committerJeff Garzik <jgarzik@redhat.com>
Wed, 25 Mar 2009 02:02:40 +0000 (24 22:02 -0400)
tree952ccc19acb1f88c29e95c0a297e7e4fe944fe13
parent08da175937a35d34a83eaefbb3458472eb1a89d4
[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>
drivers/ata/sata_mv.c