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 ESMTP id 9D2A267B6C for ; Mon, 20 Nov 2006 07:04:04 +1100 (EST) Subject: Re: [PATCH] 2.6.18-rt7: PowerPC: fix breakage in threaded fasteoi type IRQ handlers From: Benjamin Herrenschmidt To: Sergei Shtylyov In-Reply-To: <1163966437.5826.99.camel@localhost.localdomain> References: <200611192243.34850.sshtylyov@ru.mvista.com> <1163966437.5826.99.camel@localhost.localdomain> Content-Type: text/plain Date: Mon, 20 Nov 2006 07:04:09 +1100 Message-Id: <1163966649.5826.101.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, mingo@elte.hu, linux-kernel@vger.kernel.org, dwalker@mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2006-11-20 at 07:00 +1100, Benjamin Herrenschmidt wrote: > On Sun, 2006-11-19 at 22:43 +0300, Sergei Shtylyov wrote: > > As fasteoi type chips never had to define their ack() method before the > > recent Ingo's change to handle_fasteoi_irq(), any attempt to execute handler > > in thread resulted in the kernel crash. So, define their ack() methods to be > > the same as their eoi() ones... > > > > Signed-off-by: Sergei Shtylyov > > > > --- > > Since there was no feedback on three solutions I suggested, I'm going the way > > of least resistance and making the fasteoi type chips behave the way that > > handle_fasteoi_irq() is expecting from them... > > Wait wait wait .... Can somebody (Ingo ?) explain me why the fasteoi > handler is being changed and what is the rationale for adding an ack > that was not necessary before ? To be more precise, I don't see in what circumstances a fasteoi type PIC would need an ack routine that does something different than the eoi... and if it always does the same thing, why not just call eoi ? Ben.