From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
To: FD Cami <francois.cami@free.fr>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH] Re: Forcing modes in libata (was: SATA buffered read VERY
Date: Sun, 06 Jan 2008 17:13:35 +0100 [thread overview]
Message-ID: <4780FE2F.60100@dunaweb.hu> (raw)
Hi,
Once upon a time FD Cami wrote:
> On Sun, 6 Jan 2008 13:36:09 +0000
> Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>
> > On Sun, 6 Jan 2008 08:03:31 +0300
> > > > For now you can boot with libata.dma=1 to select DMA on disks but
> > > > not CD
> > >
> > > Great, but why isn't this in the documentation?
> >
> > Send patches
>
> patch attached.
>
> Description : Add libata.dma= to Documentation/kernel-parameters.txt
>
> Found documentation in :
> http://www.mail-archive.com/linux-ide%40vger.kernel.org/msg09849.html
> http://www.redhat.com/archives/fedora-extras-commits/2007-October/msg04568.html
>
> Signed-off-by: François Cami <francois.cami@free.fr>
>
> *["libata-doc-patch.txt" (text/plain)]* <http://marc.info/?l=linux-kernel&m=119963307018562&q=p3>
>
> diff -rU2 linux-2.6.24-rc6/Documentation/kernel-parameters.txt \
> linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt
> --- linux-2.6.24-rc6/Documentation/kernel-parameters.txt 2008-01-06 \
> 15:58:54.000000000 +0100
> +++ linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt 2008-01-06 \
> 16:11:20.000000000 +0100 @@ -883,4 +883,11 @@
> C2 power state.
>
> + libata.dma= [LIBATA] DMA control
> + libata.dma=0 Disable all PATA DMA like old IDE
> + libata.dma=1 Disk DMA only
> + libata.dma=2 ATAPI DMA only
> + libata.dma=3 CF DMA only
> + libata.dma=0,1,3 Combinations also work.
> +
>
The code patch you are looking at has little different semantics.
(1 << 2) is 4 not 3... Values for different devices are:
1 - ATA
2 - ATAPI
4 - CF
The parameter is a bitmask of 1, 2, 4. Default is 7.
2.6.24-rc3 also has this in libata-core.c which confirms
the acceptance of a bitmask :
static int libata_dma_mask =
ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
module_param_named(dma, libata_dma_mask, int, 0444);
MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
Best regards,
Zoltán Böszörményi
reply other threads:[~2008-01-06 16:37 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4780FE2F.60100@dunaweb.hu \
--to=zboszor@dunaweb.hu \
--cc=francois.cami@free.fr \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.