From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: PATA Sil680 Disabling IRQ Date: Fri, 29 Feb 2008 11:21:59 +0000 Message-ID: <20080229112159.2e5adbd1@core> References: <8202f4270802261647t505cccf7ra3c81e5fccc9366a@mail.gmail.com> <47C4B5BE.7010709@garzik.org> <8202f4270802271620u6cea6176p2bea5ff8e0b9bbef@mail.gmail.com> <20080228202255.5e3f0c43@core> <8202f4270802281411j747bf96dx34ff81c4d192d417@mail.gmail.com> <20080228231002.325c9e1d@core> <8202f4270802281707g6fb80dc4i6a8015cdd13035ec@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:46589 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752654AbYB2LdB (ORCPT ); Fri, 29 Feb 2008 06:33:01 -0500 In-Reply-To: <8202f4270802281707g6fb80dc4i6a8015cdd13035ec@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Fajun Chen Cc: Jeff Garzik , "linux-ide@vger.kernel.org" , Mark Lord , Tejun Heo > I agree with you and Jeff that we can not prevent superuser from > corrupting the system. What I want to understand more is if there's > room to harden PATA PIO code in libata. For instance, when I set > wrong data transfer direction in DMA read, I got command timeout, > which to me is a more graceful failure than IRQ disabling. I'm not > sure if the difference of failure mode between PIO and DMA is caused > by controller or software. If the cause is software, it would be > nice to close the gap. Its almost impossible to tell - I can't duplicate the case you see. When I issue wrong commands I see the expected timeout/fail. It may be that Tejun's drain patches for the PIO fifo are going to help in your case I don't know. Nothing obvious in the SIL680 docs hit me