All of lore.kernel.org
 help / color / mirror / Atom feed
From: Wolfgang Denk <wd@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] API for serial functions
Date: Mon, 01 Oct 2007 11:29:08 +0200	[thread overview]
Message-ID: <20071001092908.3F1B12475A@gemini.denx.de> (raw)
In-Reply-To: Your message of "Mon, 01 Oct 2007 04:15:35 EDT." <200710010415.35958.vapier@gentoo.org>

Dear Mike,

in message <200710010415.35958.vapier@gentoo.org> you wrote:
> 
> is there a document that outlines the exact expected behavior of the serial
> functions ?  specifically, i'm looking to see if the serial_putc() function

There is no such document...

> is supposed to wait until the character it is given has been fully 
> transmitted over the wire, or if it is simply required to queue the character 
> up into the hardware fifo and then return ...

While it's not a strict requirement, I would  expect  that  you  wait
until the charatcer has been sent. You have toi add some wait anway -
either  at  the  start  or  at  the end of the function, and from the
debugging point of view it makes more sense to  wait  for  completion
before  continuing.  Performancewise  there  will be no difference, I
think.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"We all agree on the necessity of compromise. We just can't agree  on
when it's necessary to compromise."
                - Larry Wall in  <1991Nov13.194420.28091@netlabs.com>

  reply	other threads:[~2007-10-01  9:29 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-01  8:15 [U-Boot-Users] API for serial functions Mike Frysinger
2007-10-01  9:29 ` Wolfgang Denk [this message]
2007-10-01  9:41   ` Mike Frysinger
2007-10-01 10:03     ` Stefan Roese
2007-10-01 10:20       ` Mike Frysinger
2007-10-01 10:43         ` Wolfgang Denk
2007-10-01 10:57           ` Mike Frysinger
2007-10-01 10:37     ` Wolfgang Denk
2007-10-01 10:54       ` Mike Frysinger

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=20071001092908.3F1B12475A@gemini.denx.de \
    --to=wd@denx.de \
    --cc=u-boot@lists.denx.de \
    /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.