From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8C344B6EF3 for ; Mon, 11 Jan 2010 08:32:36 +1100 (EST) Subject: Re: PCI-PCI bridge scanning broken on 460EX From: Benjamin Herrenschmidt To: Felix Radensky In-Reply-To: <4B4A4307.5050704@embedded-sol.com> References: <4B388D9D.7010404@embedded-sol.com> <1262584539.2173.335.camel@pasglop> <4B41ADF1.1000400@embedded-sol.com> <4B49CE8A.7000609@embedded-sol.com> <1263155906.724.2.camel@pasglop> <4B4A4307.5050704@embedded-sol.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 11 Jan 2010 08:31:57 +1100 Message-ID: <1263159117.724.15.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Stefan Roese , Feng Kan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > OK, I'll try writing byte by byte. The funny thing is the u-boot also > writes the > same value to PCI_PRIMARY_BUS register and it doesn't cause reset. Maybe the bridge doesn't want to be programmed more than once on these registers ? In any case, that's very very fishy.... I wonder if the bridge is causing a PCI reset -upstream- (which would really be a weird thing to do) and the 460 is turning that into a system reset ? Check if there are ways to control how the 460 reacts to PCI resets... In any case, it looks like a fucked up bridge to me. I don't suppose you've seen anything in the bridge data sheet or errata sheet that could explain what it's doing ? Cheers, Ben.