From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH resend regression?] AHCI: Fix threaded interrupt setup Date: Thu, 13 Nov 2014 10:06:33 +0000 Message-ID: <546482A9.20803@arm.com> References: <1415871882-634-1-git-send-email-hdegoede@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Return-path: Received: from service87.mimecast.com ([91.220.42.44]:50686 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176AbaKMKGj convert rfc822-to-8bit (ORCPT ); Thu, 13 Nov 2014 05:06:39 -0500 In-Reply-To: <1415871882-634-1-git-send-email-hdegoede@redhat.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Hans de Goede Cc: Tejun Heo , "linux-ide@vger.kernel.org" Hi Hans, On 13/11/14 09:44, Hans de Goede wrote: > Hi Tejun, > > Since this patch mentioned sunxi it gained my attention, but as it touches > ahci core code I was expecting you to pick it up, which seems to not have > happened, so hence this resend. > > FWIW I've tried to reproduce the problem, but it does not reproduce for me, > that does not mean it is not a real problem though. I'm afraid I'm to > unfamiliar with the ahci interrupt handling to say anything more sensible > about this. I can reproduce it about once every 5 boots or so. You can also notice that the interrupt rate is much higher with the threaded interrupt code, which is a sign that something is very fishy (the level interrupt is never masked...). > It looks like this is a 3.18 regression, so if this is a real issue, we > should probably get this patch in for 3.18 . I think the real fix should be to revert the whole threaded interrupt thing. Adding the IRQF_ONESHOT breaks some Intel platforms in a rather bad way in case of a shared interrupt (for gory details, see http://www.gossamer-threads.com/lists/linux/kernel/2043506). Tejun did prepare a set of patches to revert this, but I haven't seen it being pulled in yet. It would be good to get something into 3.18. Thanks, M. -- Jazz is not dead. It just smells funny...