Re: [patch 1/2] sata_via: Correctly setup PIO/DMA for pata slaveon vt6421.

From: Jeff Garzik
Date: Wed Jan 20 2010 - 14:35:28 EST

On 01/16/2010 06:56 PM, Bart Hartgers wrote:
Before only the timings for master were set. Datasheet can be found
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@xxxxxxxxx>


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