From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni) Date: Tue, 29 Sep 2015 19:55:14 +0200 Subject: [PATCH v4 1/2] ARM: dma-mapping: Don't use outer_flush_range when the L2C is coherent In-Reply-To: <20150929174835.GO21513@n2100.arm.linux.org.uk> References: <1443545458-14807-1-git-send-email-gregory.clement@free-electrons.com> <1443545458-14807-2-git-send-email-gregory.clement@free-electrons.com> <20150929171054.GN21513@n2100.arm.linux.org.uk> <20150929193031.72bbebe8@free-electrons.com> <20150929174835.GO21513@n2100.arm.linux.org.uk> Message-ID: <20150929195514.277efd80@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On Tue, 29 Sep 2015 18:48:35 +0100, Russell King - ARM Linux wrote: > > It might very well be the case. If there's enough PCIe traffic and a > > PL310 cache maintenance operation happening at the same time, the > > system will lockup. I'm a bit surprised that just the initialization of > > the PCIe card generates enough traffic to trigger the deadlock, but > > maybe I'm underestimating the problem. > > It isn't every boot - the board has booted around 240 kernels so far and > maybe 5% of them have needed the reset button pressed because of this. > It only happens when I have the SATA card connected. I don't have any > drives on the SATA card at the moment though. Hum, ok. Then I'm not sure it's the same problem. I believe it's unlikely that the few PCIe accesses used just to enumerate the PCIe device and initialize it are enough to cause the deadlock. But I don't have (and anyway wouldn't fully understand) all the details about this issue, so I can't say for sure. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from down.free-electrons.com ([37.187.137.238]:57810 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932797AbbI2R4F (ORCPT ); Tue, 29 Sep 2015 13:56:05 -0400 Date: Tue, 29 Sep 2015 19:55:14 +0200 From: Thomas Petazzoni To: Russell King - ARM Linux Cc: Gregory CLEMENT , Catalin Marinas , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Ezequiel Garcia , linux-arm-kernel@lists.infradead.org, Maxime Ripard , Boris BREZILLON , Lior Amsalem , Tawfik Bayouk , Nadav Haklai , stable@vger.kernel.org Subject: Re: [PATCH v4 1/2] ARM: dma-mapping: Don't use outer_flush_range when the L2C is coherent Message-ID: <20150929195514.277efd80@free-electrons.com> In-Reply-To: <20150929174835.GO21513@n2100.arm.linux.org.uk> References: <1443545458-14807-1-git-send-email-gregory.clement@free-electrons.com> <1443545458-14807-2-git-send-email-gregory.clement@free-electrons.com> <20150929171054.GN21513@n2100.arm.linux.org.uk> <20150929193031.72bbebe8@free-electrons.com> <20150929174835.GO21513@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: Hello, On Tue, 29 Sep 2015 18:48:35 +0100, Russell King - ARM Linux wrote: > > It might very well be the case. If there's enough PCIe traffic and a > > PL310 cache maintenance operation happening at the same time, the > > system will lockup. I'm a bit surprised that just the initialization of > > the PCIe card generates enough traffic to trigger the deadlock, but > > maybe I'm underestimating the problem. > > It isn't every boot - the board has booted around 240 kernels so far and > maybe 5% of them have needed the reset button pressed because of this. > It only happens when I have the SATA card connected. I don't have any > drives on the SATA card at the moment though. Hum, ok. Then I'm not sure it's the same problem. I believe it's unlikely that the few PCIe accesses used just to enumerate the PCIe device and initialize it are enough to cause the deadlock. But I don't have (and anyway wouldn't fully understand) all the details about this issue, so I can't say for sure. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com