Re: 2.6.29-rc libata sff 32bit PIO regression

[Jeff Garzik <jeff@garzik.org>]

Alan Cox wrote:
>> [PATCH] libata sff: 32bit PIO use 16bit on slop
>>
>> 871af1210f13966ab911ed2166e4ab2ce775b99d libata: Add 32bit PIO support
>> causes errors on a four-year-old ata_piix Dell Precision 670.  Using
>> 16bit PIO instead of 32bit PIO on the odd 1, 2 or 3 chars fixes that.
>>
>> Signed-off-by: Hugh Dickins <hugh@veritas.com>
> 
> For the 3 bytes of slop it should use a single iowrite32 but otherwise
> that seems ok. We do need to handle the FIFO setup on the AMD differently
> if we do this - something like this:
> 
> pata_amd: Program FIFO
> 
> From: Alan Cox <alan@lxorguk.ukuu.org.uk>
> 
> With 32bit PIO we can use the posted write buffers, but only for 32bit I/O
> cycles. This means we must disable the FIFO for ATAPI where a final 16bit
> cycle may occur.
> 
> Rework the FIFO logic so that we disable the FIFO then selectively re-enable
> it when we set the timings on AMD devices. Also fix a case where we scribbled
> on PCI config 0x41 of Nvidia chips when we shouldn't.
> 
> Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
> ---
> 
>  drivers/ata/pata_amd.c |   78 +++++++++++++++++++++++++++++++++++++-----------
>  1 files changed, 60 insertions(+), 18 deletions(-)

tested and ok for -rc?