From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3CFB7595.AF86DFF0@ssh.com> Date: Mon, 03 Jun 2002 16:56:37 +0300 From: Arto Vuori MIME-Version: 1.0 To: acurtis@onz.com Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: 8260 IDMA experience? References: Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Allen Curtis wrote: > So it works but it may not be as fast as a memcpy(). Sounds like more > testing is required to determine the overall benefit of freeing the > processor. Right. We are using IDMA only for accessing slow devices, so that CPU don't need to wait for the data and can do some usefull work simultaneously. > > > I did also notice that when i am doing memory-to-peripheral (or > > vice-versa) transfers, IDMA corrupts simultaneous Ethernet traffic > > unless IDMA is set to low-priority mode. Same might apply for > > memory-to-memory transfers. > > What 8260 chip revision are you using? I have found lots of problems when > rev A processors but rev C has been much better. I have done most of my testing with revision A chips. I've had many problems with those chips and it took some time with logic analyzer to debug those IDMA transfers before i got them working. Arto -- Arto Vuori email: avuori@ssh.com mobile: +358 40 754 5223 ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/