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Date:      Thu, 28 Jan 2016 09:44:50 +0100
From:      Norbert Koch <nkoch@demig.de>
To:        <freebsd-hackers@FreeBSD.org>
Subject:   impossible to set pata dma mode?
Message-ID:  <56A9D502.7010809@demig.de>

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Hello.

I have to reduce dma mode from udma to wdma2
for a flash device.

In the past this was easy using atacontrol
but, afaiks it seems to be impossible using camcontrol.

 camcontrol negotiate ada0 -M wdma
...You can only modify user parameters

 camcontrol negotiate ada0 -NM wdma
Works, but I see no way how those user
parameters become active parameters as the
driver only reads then in attach as far as
I can see.

It seems like the ata driver's interface
allows to change the current settings
(XPT_SET_TRAN_SETTINGS/CTS_TYPE_CURRENT_SETTINGS)
so, why is camcontrol so restrictive?

Thank you,
Norbert Koch



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