From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Kernel - Noah Blumenfeld <kernel@fireether.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: IT821x driver
Date: Sun, 18 Dec 2005 12:05:08 +0000 [thread overview]
Message-ID: <1134907508.26141.8.camel@localhost.localdomain> (raw)
In-Reply-To: <43A54683.3030202@fireether.net>
On Sul, 2005-12-18 at 06:22 -0500, Kernel - Noah Blumenfeld wrote:
> As far as I can tell - and from the information within the driver's file
> /drivers/ide/pci/it821x.c - the current driver does not support mwdma
> or dma, only udma. It also says that if - and I quote Alan Cox -
The 2.6.14 kernel has a version of the driver built in that should
support all modes properly. In hardware raid mode DMA mode selection is
handled by the controller and we actually don't deal with it.
In pass through/atapi supporting mode we handle the mode selection and
support MWDMA/UDMA. The chip is really designed to be best for UDMA (as
you'd expect) but does handle other modes.
> Is there a way to restrict the size of the files being written by the
> kernel to a hardware device? I.e. make it so it will not write LBA48
We do the following in init_hwif_it821x already
if(conf & 1) {
idev->smart = 1;
hwif->atapi_dma = 0;
/* Long I/O's although allowed in LBA48 space cause the
onboard firmware to enter the twighlight zone */
hwif->rqsize = 256;
}
So the driver should be doing this correctly. Also for DMA on the smart
mode, use hdparm -d1, but don't try and program the drives - that is
handled by the controller and that may be upsetting it. Let me know if
that helps.
If you are doing raid0 btw its faster in non-raid mode and using
software raid. In raid1 it seems to be faster to use the chip in smart
mode.
Alan
prev parent reply other threads:[~2005-12-18 12:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-18 11:22 IT821x driver Kernel - Noah Blumenfeld
2005-12-18 12:05 ` Alan Cox [this message]
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=1134907508.26141.8.camel@localhost.localdomain \
--to=alan@lxorguk.ukuu.org.uk \
--cc=kernel@fireether.net \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox