From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay04.roc.ny.frontiernet.net (relay04.roc.ny.frontiernet.net [66.133.182.167]) by ozlabs.org (Postfix) with ESMTP id 1AFEB67A3E for ; Thu, 12 May 2005 21:29:38 +1000 (EST) Message-ID: <006101c556e5$ebbfeb10$0301a8c0@chuck2> From: "Mark Chambers" To: "Pantelis Antoniou" References: <20050510154145.GB8444@logos.cnet> <001701c555af$c8ca0e10$0301a8c0@chuck2> <4282F263.8080501@intracom.gr> Date: Thu, 12 May 2005 07:29:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Cc: linux-ppc-embedded Subject: Re: m8xx_pcmcia driver ported to v2.6 List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > >>There is one pending problem: the M8xx does not accept > >>access to non present ioports (an exception is triggered), > >>which is quite common while inserting/removing cards. > >> > > Ah yes, I remember this problem from the 68360 days. > > > > This is a matter of how you set up the option register ORx > > > > for instance, you could turn external ack on once a card > > was inserted. > > > > As I recall, some PCMCIA cards can have VERY long > > cycles in the configuration space, so even the maximum > > number of wait states in ORx may not be sufficient. > > > Unfortunately this does not work on 8xx since the PCMCIA > port is not on a chip select. It's a different peripheral > and always expectes a DTACK to terminate the cycle. > > To get over this problem we need to do something more drastic. > > Take a look at the __do_in_asm macro in include/asm-ppc/io.h. > > Regards > > Pantelis > You are right, I had forgotten that. I'd also forgotten that PCMCIA uses negative WAIT, which should have a pull-up on it, so there should be no problem with non-existent cards. Another potential problem could be the Bus Monitor Timeout being set too short and generating a TEA before a valid WAIT is released. Mark Chambers