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

From: Tejun Heo
Date: Tue Jan 19 2010 - 22:27:19 EST


On 01/17/2010 08:56 AM, Bart Hartgers wrote:
> 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@xxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

--
tejun
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