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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Marc Leeman <marc.leeman@barco.com>
Cc: linuxppc-dev list <linuxppc-dev@lists.linuxppc.org>
Subject: Re: PCI Memory mapping
Date: Wed, 24 Mar 2004 11:04:00 +1100	[thread overview]
Message-ID: <1080086640.23208.164.camel@gaston> (raw)
In-Reply-To: <20040323111736.GJ1446@smtp.barco.com>


On Tue, 2004-03-23 at 22:17, Marc Leeman wrote:

> When data is passed to the DSP and every buffer is confirmed with an
> [Enter] (i.e. __very__ slow_), data is passed correctly. When we try to
> pass the same data without user intervention (comment out
> waitforenter()),
> parts of the transferred data are copied from other locations: most of
> the time, part of the buffer (e.g. 2048 bytes) is not update yet (old
> data).

One thing is: after having written your data to the consistent buffer,
you should make sure you have proper ordering with the MMIO write you
do to kick the DSP. On most CPUs, eieio appear to be enough and I
wouldn't suppose the 8245 to heavily reorder, but just in case, try
adding a sync.

Ben.


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

  parent reply	other threads:[~2004-03-24  0:04 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-16 11:40 PCI Memory mapping Marc Leeman
2004-03-16 16:39 ` Jeff Angielski
2004-03-22  7:48   ` Marc Leeman
2004-03-22 11:02     ` Marc Leeman
2004-03-23 11:17     ` Marc Leeman
2004-03-23 16:01       ` Marc Leeman
2004-03-24  2:04         ` Michael R. Zucca
2004-03-24  0:04       ` Benjamin Herrenschmidt [this message]
2004-03-24 12:26         ` Marc Leeman
2004-03-24 14:25           ` Marc Leeman
2004-03-24 17:08             ` linas
2004-03-25 15:48               ` Marc Leeman
2004-03-25 16:34                 ` linas
2004-03-25 16:45                   ` linas
2004-03-26  8:00                     ` Marc Leeman
2004-03-30 19:49                       ` Jeff Angielski
2004-03-31 15:56                         ` Marc Leeman
2004-03-31 16:02                           ` Marc Leeman
2004-04-01 12:33                           ` Marc Leeman
2004-04-04 22:53                             ` Benjamin Herrenschmidt
2004-04-05  8:46                             ` Adrian Cox
     [not found]                             ` <20040402140130.GG22365@smtp.barco.com>
     [not found]                               ` <1081175362.20952.30.camel@localhost.localdomain>
2004-04-06  6:21                                 ` Marc Leeman
  -- strict thread matches above, loose matches on Subject: below --
2004-04-07  7:15 Marc Leeman
2011-04-15  5:44 koteswararaom
2011-04-15  6:32 ` David Hawkins
2011-04-15  6:48 ` Michael Neuling

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