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author | Bart Hartgers <bart.hartgers@gmail.com> | 2010-01-16 18:56:54 -0500 |
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committer | Jeff Garzik <jgarzik@redhat.com> | 2010-03-01 14:58:44 -0500 |
commit | 02d1d6160ffe13f4ebc6f85f72366a5da0b1fb9b (patch) | |
tree | 3798274cf1cd116ef7238a8ca32a853bbca13708 /Documentation/video-output.txt | |
parent | 9ffc5da5e1e57592da9c22d83a98c63afc8d985c (diff) |
sata_via: Correctly setup PIO/DMA for pata slave on vt6421.
Before only the timings for master were set. Datasheet can be found
here: ftp://ftp.vtbridge.org/Docs/Storage/DS_VT6421A_100_CCPL.PDF
Surprisingly, a slave drive works without this patch. According to the
datasheet, the controller by default derives the DMA mode from the
Set Features command issued to a drive. Not sure about the PIO
timings, though. The real problem is that the timings for the master
effectively are the ones tuned for the slave. If these support
different UDMA-settings, there is trouble, especially when the slave
supports a higher UDMA than the master.
Anyhow, using the same mechanism for both master and slave seems like
a good idea.
Signed-off-by: Bart Hartgers <bart.hartgers@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'Documentation/video-output.txt')
0 files changed, 0 insertions, 0 deletions