From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91BFBC49ED7 for ; Tue, 10 Sep 2019 17:38:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 682412168B for ; Tue, 10 Sep 2019 17:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437031AbfIJRi2 (ORCPT ); Tue, 10 Sep 2019 13:38:28 -0400 Received: from foss.arm.com ([217.140.110.172]:38674 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727086AbfIJRi2 (ORCPT ); Tue, 10 Sep 2019 13:38:28 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 52E891000; Tue, 10 Sep 2019 10:38:25 -0700 (PDT) Received: from red-moon.cambridge.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 446953F71F; Tue, 10 Sep 2019 10:38:22 -0700 (PDT) Date: Tue, 10 Sep 2019 18:38:15 +0100 From: Lorenzo Pieralisi To: Bjorn Helgaas Cc: Jonathan Chocron , jingoohan1@gmail.com, gustavo.pimentel@synopsys.com, robh+dt@kernel.org, mark.rutland@arm.com, andrew.murray@arm.com, dwmw@amazon.co.uk, benh@kernel.crashing.org, alisaidi@amazon.com, ronenk@amazon.com, barakw@amazon.com, talel@amazon.com, hanochu@amazon.com, hhhawa@amazon.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v5 4/7] PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port Message-ID: <20190910173815.GA6712@red-moon.cambridge.arm.com> References: <20190905140018.5139-1-jonnyc@amazon.com> <20190905140018.5139-5-jonnyc@amazon.com> <20190907165542.GN103977@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190907165542.GN103977@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Sat, Sep 07, 2019 at 11:55:42AM -0500, Bjorn Helgaas wrote: > s/Add quirk to disable/Disable/ in subject > > On Thu, Sep 05, 2019 at 05:00:18PM +0300, Jonathan Chocron wrote: > > The Root Port (identified by [1c36:0031]) doesn't support MSI-X. On some > > platforms it is configured to not advertise the capability at all, while > > on others it (mistakenly) does. This causes a panic during > > initialization by the pcieport driver, since it tries to configure the > > MSI-X capability. Specifically, when trying to access the MSI-X table > > a "non-existing addr" exception occurs. > > MSI-X configuration is all in memory space (not config space), so I > guess this device has a BAR (maybe more) and the MSI-X table access > would be to something in that BAR? Or is there junk in the capability > so we try to access something completely outside the BAR? [I wonder if > it'd be worth adding some validation to make sure the Table and PBA > areas are contained in the BAR?] > > The reason I'm curious about all this is because on the PCI side this > is probably an Unsupported Request or similar error, and on *most* > platforms, this does not cause a panic. If it was a read, the read > usually gets ~0 data, and writes are dropped. > > So my concern is that we'll avoid this panic by disabling MSI, but > we'll see other panics in other places. > > > Example stacktrace snippet: > > [Remove the timestamps since they're not really relevant and indent > the quote a couple spaces] Jonathan, can you please clarify and update the patch so that we can proceed with the series and try to get it into v5.4 ? Thanks, Lorenzo > > > [ 1.632363] SError Interrupt on CPU2, code 0xbf000000 -- SError > > [ 1.632364] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-Jonny-14847-ge76f1d4a1828-dirty #33 > > [ 1.632365] Hardware name: Annapurna Labs Alpine V3 EVP (DT) > > [ 1.632365] pstate: 80000005 (Nzcv daif -PAN -UAO) > > [ 1.632366] pc : __pci_enable_msix_range+0x4e4/0x608 > > [ 1.632367] lr : __pci_enable_msix_range+0x498/0x608 > > [ 1.632367] sp : ffffff80117db700 > > [ 1.632368] x29: ffffff80117db700 x28: 0000000000000001 > > [ 1.632370] x27: 0000000000000001 x26: 0000000000000000 > > [ 1.632372] x25: ffffffd3e9d8c0b0 x24: 0000000000000000 > > [ 1.632373] x23: 0000000000000000 x22: 0000000000000000 > > [ 1.632375] x21: 0000000000000001 x20: 0000000000000000 > > [ 1.632376] x19: ffffffd3e9d8c000 x18: ffffffffffffffff > > [ 1.632378] x17: 0000000000000000 x16: 0000000000000000 > > [ 1.632379] x15: ffffff80116496c8 x14: ffffffd3e9844503 > > [ 1.632380] x13: ffffffd3e9844502 x12: 0000000000000038 > > [ 1.632382] x11: ffffffffffffff00 x10: 0000000000000040 > > [ 1.632384] x9 : ffffff801165e270 x8 : ffffff801165e268 > > [ 1.632385] x7 : 0000000000000002 x6 : 00000000000000b2 > > [ 1.632387] x5 : ffffffd3e9d8c2c0 x4 : 0000000000000000 > > [ 1.632388] x3 : 0000000000000000 x2 : 0000000000000000 > > [ 1.632390] x1 : 0000000000000000 x0 : ffffffd3e9844680 > > [ 1.632392] Kernel panic - not syncing: Asynchronous SError Interrupt > > [ 1.632393] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-Jonny-14847-ge76f1d4a1828-dirty #33 > > [ 1.632394] Hardware name: Annapurna Labs Alpine V3 EVP (DT) > > [ 1.632394] Call trace: > > [ 1.632395] dump_backtrace+0x0/0x140 > > [ 1.632395] show_stack+0x14/0x20 > > [ 1.632396] dump_stack+0xa8/0xcc > > [ 1.632396] panic+0x140/0x334 > > [ 1.632397] nmi_panic+0x6c/0x70 > > [ 1.632398] arm64_serror_panic+0x74/0x88 > > [ 1.632398] __pte_error+0x0/0x28 > > [ 1.632399] el1_error+0x84/0xf8 > > [ 1.632400] __pci_enable_msix_range+0x4e4/0x608 > > [ 1.632400] pci_alloc_irq_vectors_affinity+0xdc/0x150 > > [ 1.632401] pcie_port_device_register+0x2b8/0x4e0 > > [ 1.632402] pcie_portdrv_probe+0x34/0xf0 > > > > Notice that this quirk also disables MSI (which may work, but hasn't > > been tested nor has a current use case), since currently there is no > > standard way to disable only MSI-X. > > > > Signed-off-by: Jonathan Chocron > > Reviewed-by: Gustavo Pimentel > > Reviewed-by: Andrew Murray > > --- > > drivers/pci/quirks.c | 18 ++++++++++++++++++ > > 1 file changed, 18 insertions(+) > > > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > > index 8fe765592943..5a8ea5fdeae7 100644 > > --- a/drivers/pci/quirks.c > > +++ b/drivers/pci/quirks.c > > @@ -2977,6 +2977,24 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x10a1, > > quirk_msi_intx_disable_qca_bug); > > DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0xe091, > > quirk_msi_intx_disable_qca_bug); > > + > > +/* > > + * Amazon's Annapurna Labs 1c36:0031 Root Ports don't support MSI-X, so it > > + * should be disabled on platforms where the device (mistakenly) advertises it. > > + * > > + * Notice that this quirk also disables MSI (which may work, but hasn't been > > + * tested), since currently there is no standard way to disable only MSI-X. > > + * > > + * The 0031 device id is reused for other non Root Port device types, > > + * therefore the quirk is registered for the PCI_CLASS_BRIDGE_PCI class. > > + */ > > +static void quirk_al_msi_disable(struct pci_dev *dev) > > +{ > > + dev->no_msi = 1; > > + pci_warn(dev, "Disabling MSI/MSI-X\n"); > > +} > > +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, > > + PCI_CLASS_BRIDGE_PCI, 8, quirk_al_msi_disable); > > #endif /* CONFIG_PCI_MSI */ > > > > /* > > -- > > 2.17.1 > >