From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755270AbcH3PCO (ORCPT ); Tue, 30 Aug 2016 11:02:14 -0400 Received: from foss.arm.com ([217.140.101.70]:42246 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752517AbcH3PCK (ORCPT ); Tue, 30 Aug 2016 11:02:10 -0400 Subject: Re: [PATCH 3/3] PCI: Xilinx NWL PCIe: Fix Error for multi function device for legacy interrupts. To: Bharat Kumar Gogada , "robh@kernel.org" , "bhelgaas@google.com" , "colin.king@canonical.com" , Soren Brinkmann , Michal Simek , "arnd@arndb.de" References: <1472553558-27215-1-git-send-email-bharatku@xilinx.com> <1472553558-27215-3-git-send-email-bharatku@xilinx.com> <57C57975.7040306@arm.com> <8520D5D51A55D047800579B094147198258D239D@XAP-PVEXMBX01.xlnx.xilinx.com> Cc: "linux-arm-kernel@lists.infradead.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ravikiran Gummaluri From: Marc Zyngier X-Enigmail-Draft-Status: N1110 Organization: ARM Ltd Message-ID: <57C59FE8.30307@arm.com> Date: Tue, 30 Aug 2016 16:02:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.7.0 MIME-Version: 1.0 In-Reply-To: <8520D5D51A55D047800579B094147198258D239D@XAP-PVEXMBX01.xlnx.xilinx.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/08/16 15:13, Bharat Kumar Gogada wrote: >> Hi Bharat, >>> @@ -561,7 +561,7 @@ static int nwl_pcie_init_irq_domain(struct nwl_pcie >> *pcie) >>> } >>> >>> pcie->legacy_irq_domain = irq_domain_add_linear(legacy_intc_node, >>> - INTX_NUM, >>> + INTX_NUM + 1, >>> &legacy_domain_ops, >>> pcie); >> >> This feels like the wrong thing to do. You have INTX_NUM irqs, so the domain >> allocation should reflect this. On the other hand, the way the driver currently >> deals with mappings is quite broken (consistently adding 1 to the HW interrupt). >> > Hi Marc, > > Without above change I get following crash in kernel while booting. > > [ 2.441684] error: hwirq 0x4 is too large for dummy > > [ 2.441694] ------------[ cut here ]------------ > > [ 2.441698] WARNING: at kernel/irq/irqdomain.c:344 > > [ 2.441702] Modules linked in: > > [ 2.441706] > > [ 2.441714] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.4.0 #8 > > [ 2.441718] Hardware name: xlnx,zynqmp (DT) > > [ 2.441723] task: ffffffc071886b80 ti: ffffffc071888000 task.ti: ffffffc071888000 > > [ 2.441732] PC is at irq_domain_associate+0x138/0x1c0 > > [ 2.441738] LR is at irq_domain_associate+0x138/0x1c0 > > In kernel/irq/irqdomain.c function irq_domain_associate > > if (WARN(hwirq >= domain->hwirq_max, > "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name)) > return -EINVAL; > > Here the hwirq and hwirq_max are equal to 4 without the above condition (INTX_NUM + 1) due to which crash is coming. > This is happening as the legacy interrupts are starting from 1 (INTA). I understood that. I'm still persisting in saying that you have the wrong fix. Your domain should always allocate many interrupts as you have interrupt sources. These interrupts (hwirq) should be numbered from 0 to (n-1). > And I'm consistently adding 1 to the HW interrupt as in > nwl_pcie_leg_handler I get 0th bit set from MSGF_LEG_STATUS if INTA > interrupt is raised but my hwirq number being mapped for INTA is 0x1 > so that's I'm adding 1 to obtain correct virtual irq. Same case in > nwl_pcie_free_irq_domain since hwirq starts from one I'm adding 1 to > obtain virtual irq and free it. I can see that. Nonetheless, this is wrong. Can you please test the patch I provided in my reply and report what happens? Thanks, M. -- Jazz is not dead. It just smells funny...