All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Lord <liml@rtr.ca>
To: Robert Hancock <hancockrwd@gmail.com>
Cc: Philippe De Muyter <phdm@macqel.be>,
	linux-ide@vger.kernel.org, davem@davemloft.net,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH ide] : Increase WAIT_DRQ to support slow CF cards
Date: Sat, 31 Oct 2009 09:56:26 -0400	[thread overview]
Message-ID: <4AEC420A.9030502@rtr.ca> (raw)
In-Reply-To: <4AE64031.5060105@gmail.com>

Robert Hancock wrote:
..
> This has come up before:
> 
> http://marc.info/?l=linux-ide&m=123064513313466&w=2
> 
> I think this timeout should not even exist. libata has no such timeout 
> (only the overall command completion timeout), and I can't find any 
> reference in current ATA specs to the device being required to raise DRQ 
> in any particular amount of time.
..

The reason for the original (20ms, then 50ms) timeout was this text
from the ATA1 specification, long since outdated:

   -  Upon receipt of a Class 3 command, the drive sets BSY within 400 nsec,
      sets  up the sector buffer for a write operation, sets DRQ within 20
      msec, and clears BSY within 400 nsec of setting DRQ.

Cheers

  parent reply	other threads:[~2009-10-31 13:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-26 16:20 [PATCH ide] : Increase WAIT_DRQ to support slow CF cards Philippe De Muyter
2009-10-27  0:34 ` Robert Hancock
2009-10-27  0:45   ` David Miller
2009-10-27  1:07     ` Robert Hancock
2009-10-27  1:19       ` David Miller
2009-10-27  1:40         ` Robert Hancock
2009-10-27  1:43           ` David Miller
2009-10-27  9:45             ` Philippe De Muyter
2009-10-27 10:24               ` Sergei Shtylyov
2009-10-31 13:56   ` Mark Lord [this message]
2009-12-03  5:57     ` David Miller
2009-12-03  8:55       ` Philippe De Muyter

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=4AEC420A.9030502@rtr.ca \
    --to=liml@rtr.ca \
    --cc=davem@davemloft.net \
    --cc=hancockrwd@gmail.com \
    --cc=linux-ide@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=phdm@macqel.be \
    /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.