All of lore.kernel.org
 help / color / mirror / Atom feed
From: William Lee Irwin III <wli@holomorphy.com>
To: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PRD_ENTRIES is 256
Date: Wed, 25 Feb 2004 05:18:17 -0800	[thread overview]
Message-ID: <20040225131817.GK693@holomorphy.com> (raw)
In-Reply-To: <200402251411.13945.bzolnier@elka.pw.edu.pl>

On Wednesday 25 of February 2004 10:53, William Lee Irwin III wrote:
>> PRD_ENTRIES is specified to be precisely 256; on platforms where
>> PAGE_SIZE varies from 4KB the calculation in the current expression
>> defining it is inaccurate, which may cause crashes. This patch changes
>> it to the constant literal 256.

On Wed, Feb 25, 2004 at 02:11:13PM +0100, Bartlomiej Zolnierkiewicz wrote:
> Ok, thanks.  However I cannot find 256 entries limit in any ATA document
> and from looking at the code 512 entries shouldn't be a problem (?).
> --bart

The numbers I'm fishing out of things say that the PRD table can't
exceed 64KB in size as it can't cross a 64KB boundary and its length
is specified as a 16-bit byte count, so some other method of sizing
the thing may be in order. I do recall something went wrong at the
time I ran into this. If I turn up where I thought the number 256 came
from I'll cite it.


-- wli

  reply	other threads:[~2004-02-25 13:18 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-02-25  9:53 PRD_ENTRIES is 256 William Lee Irwin III
2004-02-25 13:11 ` Bartlomiej Zolnierkiewicz
2004-02-25 13:18   ` William Lee Irwin III [this message]
2004-02-25 16:15   ` Jeff Garzik

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=20040225131817.GK693@holomorphy.com \
    --to=wli@holomorphy.com \
    --cc=B.Zolnierkiewicz@elka.pw.edu.pl \
    --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.