From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 08 Dec 2004 21:20:47 +0000 (GMT) Received: from 67-121-164-6.ded.pacbell.net ([IPv6:::ffff:67.121.164.6]:44240 "EHLO mailserver.sunrisetelecom.com") by linux-mips.org with ESMTP id ; Wed, 8 Dec 2004 21:20:43 +0000 Received: from there ([192.168.50.222]) by mailserver.sunrisetelecom.com with Microsoft SMTPSVC(5.0.2195.6713); Wed, 8 Dec 2004 13:20:36 -0800 Content-Type: text/plain; charset="iso-8859-1" From: Karl Lessard To: Michael Kelly Subject: Re: Epson13806 performances on Pb1100 Date: Wed, 8 Dec 2004 16:17:59 -0500 X-Mailer: KMail [version 1.3.2] Cc: Pete Popov , linux-mips@linux-mips.org References: <6.2.0.14.2.20041208153445.03ed3c70@pop3.cedata.com> In-Reply-To: <6.2.0.14.2.20041208153445.03ed3c70@pop3.cedata.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID: X-OriginalArrivalTime: 08 Dec 2004 21:20:37.0089 (UTC) FILETIME=[C2B1D510:01C4DD6B] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 6608 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: klessard@sunrisetelecom.com Precedence: bulk X-list: linux-mips On December 8, 2004 03:37 pm, Michael Kelly wrote: > KArl, > > There is a bug (they might call it a feature) that causes the Au1100 > to perform two accesses when talking to 16-bit peripherals. The > first access is the real one, while the second access has the byte > enables off. But, this means every access creates two cycles on > the bus. > > I am sure of this bug on the standard peripheral bus, and I am pretty > sure it still exists when talking via the LCD signals, since the same > bus controller is used. > > MIchael Well, that may cause a problem of course. Do you mean that writing 8-bit or 16-bits data through a chip select configured for 16-bit data bus will send in fact two write signals? If it is the case, then I obviously need to send 32-bit data for every access, since the second write will be used to send the second word (I suppose). Do I understand well? > > At 02:38 PM 12/8/2004, Karl Lessard wrote: > > > I've used the chip with the 2.4 kernel/driver to run X and some > > > apps. I'm not sure what you mean by high performance -- does X run > > > at reasonable speeds? > > > >I'm not running X, I've just runned a little application that writes a > > number of vertical lines (so pixel per pixel) in a backbuffer and then > > blit its content to the screen. Here's an example of one frame: > > > >__u8 *dest = (__u8*)back_buffer; > >memset(dest, 0, back_buffer_size); /* clear back buffer */ > > > >for (i = 0; i < 500; i++) { /* 500 lines */ > > for (j = 0; j >= 100; j--) { /* of 100 pixel each */ > > dest[(j * fb_width) + i] = 0xFF; > > } > >} > > > >memcpy(front_buffer, dest, back_buffer_size); /* copy back_buffer to > > front */ > > > > > >Benching with 500 frames, I obtain a rate of 8 fps with the backbuffer > >residing in video memory. The framerate increase to 31 fps when the > > backbuffer is in system memory! And if I do the same test using the > > Au1100 lcd controller (which has its front and back buffer in system > > memory), It goes up to 66 fps... > > > >I don't know what's going on when I try to access the 13806 controller, > > but it's really too slow. And using the blit engine don't helps much. The > > static controller seems to be set correctly. By the way, the DRAM is > > refreshing at 96Hz, and my CRT display is refreshing at 66Hz. > > > >Any Idea? By the way Dan, I've tried the cache trick, but no luck. > > > >Thanks a lot, > >Karl > > > > > Pete > > > > > > > I would like to know if anyone have encountered this performance > > > > problem in the past with this chip. > > > > > > > > Thanks in advance, > > > > Karl > > Michael J. Kelly > VP Engineering/Marketing > Cogent Computer Systems, Inc. > 1130 Ten Rod Road > Suite A-201 > North Kingstown, RI 02852 > tel:401-295-6505 fax:401-295-6507 > www.cogcomp.com > alternate email: mkelly6505@hotmail.com