From: Jeff Garzik <jeff@garzik.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Robert Hancock <hancockr@shaw.ca>,
Zoltan Boszormenyi <zboszor@dunaweb.hu>,
Peer Chen <pchen@nvidia.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drivers/ata: Add the SW NCQ support to sata_nv for MCP51/MCP55/MCP61
Date: Fri, 18 May 2007 10:34:35 -0400 [thread overview]
Message-ID: <464DB97B.8030204@garzik.org> (raw)
In-Reply-To: <20070518133456.5f1392e9@the-village.bc.nu>
Alan Cox wrote:
>> That shouldn't be a problem, libata default DMA mask is 32 bits (which
>> isn't overridden with this controller) and so the block layer will
>> bounce any data being read/written above that point with IOMMU or
>> swiotlb. The comment is a bit unnecessarily scary.
>
> Adding a BUG_ON for this would be wise. Its trivial to check and a BUG
> rather than corruption if this assumption ever changes would be far
> preferable
The default DMA mask -everywhere- is 32 bits.
A lot of code will break if this assumption ever changes, not just libata.
Jeff
next prev parent reply other threads:[~2007-05-18 14:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.iernIz8Xcuvw0SBwi4A99Ju0g2o@ifi.uio.no>
2007-05-18 1:58 ` [PATCH] drivers/ata: Add the SW NCQ support to sata_nv for MCP51/MCP55/MCP61 Robert Hancock
2007-05-18 12:34 ` Alan Cox
2007-05-18 14:34 ` Jeff Garzik [this message]
2007-05-18 15:12 ` Alan Cox
2007-05-20 8:34 ` Zoltan Boszormenyi
[not found] <fa.NGBsZzMiMJ9x7V/pv+sqAv36hwA@ifi.uio.no>
2007-05-18 23:31 ` Robert Hancock
2007-05-18 11:10 Kuan Luo
2007-05-18 11:10 ` Kuan Luo
-- strict thread matches above, loose matches on Subject: below --
2007-05-17 21:02 Zoltan Boszormenyi
2007-05-15 6:22 [PATCH] drivers/ata: correct a wrong free function for sata_nv driver Peer Chen
2007-05-16 5:21 ` Jeff Garzik
2007-05-17 10:15 ` [PATCH] drivers/ata: Add the SW NCQ support to sata_nv for MCP51/MCP55/MCP61 Peer Chen
2007-05-17 20:12 ` Andrew Morton
2007-05-17 20:17 ` Andrew Morton
2007-05-17 21:11 ` Jan Engelhardt
2007-05-18 1:47 ` Robert Hancock
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=464DB97B.8030204@garzik.org \
--to=jeff@garzik.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=hancockr@shaw.ca \
--cc=linux-kernel@vger.kernel.org \
--cc=pchen@nvidia.com \
--cc=zboszor@dunaweb.hu \
/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.