From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3CFB620E.9F8643EB@ssh.com> Date: Mon, 03 Jun 2002 15:33:18 +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: > > Does anyone have experience with IDMA on the 8260? Are there any special > considerations if you wanted to use the memory-to-memory copy function in > place of a memcpy()? (kernel memory only at this time) I have been using IDMA to transfer data between kernel memory and a FPGA. I also did some testing with memory-to-memory transfers and i didn't find them to be worth the trouble. Performance ain't that great. You probably get more speed by copying with your CPU, though you might avoid some cache trashing. 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. Arto -- Arto Vuori email: avuori@ssh.com mobile: +358 40 754 5223 ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/