Re: [PATCH] libata: Fix a large collection of DMA mode mismatches

[Jeff Garzik <jgarzik@pobox.com>]

Alan Cox wrote:
> From: Alan Cox <alan@redhat.com>
> 
> Dave Müller sent a diff for the pata_oldpiix that highlighted a problem
> where a lot of the ATA drivers assume dma_mode == 0 means "no DMA" while
> the core code uses 0xFF.
> 
> This turns out to have other consequences such as code doing >= XFER_UDMA_0
> also catching 0xFF as UDMAlots. Fortunately it doesn't generally affect
> set_dma_mode, although some drivers call back into their own set mode code
> from other points.
> 
> Having been through the drivers I've added helpers for using_udma/using_mwdma
> dma_enabled so that people don't open code ranges that may change (eg if UDMA8
> appears somewhere)
> 
> Thanks to David for the initial bits
> 
> Signed-off-by: Alan Cox <alan@redhat.com>
> ---
> 
>  drivers/ata/libata-core.c |    4 ++--
>  drivers/ata/pata_acpi.c   |    2 +-
>  drivers/ata/pata_atiixp.c |    2 +-
>  drivers/ata/pata_cs5530.c |    6 +++---
>  drivers/ata/pata_sc1200.c |    6 +++---
>  include/linux/libata.h    |   22 ++++++++++++++++++++++
>  6 files changed, 32 insertions(+), 10 deletions(-)

applied (w/ David's pata_oldpiix update)