From 738cb37b013e5ba6abd725a22abbd8baebc95082 Mon Sep 17 00:00:00 2001 From: Jonathan Chocron Date: Thu, 12 Sep 2019 16:00:42 +0300 Subject: [PATCH] PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port 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. Example stacktrace snippet: SError Interrupt on CPU2, code 0xbf000000 -- SError CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-Jonny-14847-ge76f1d4a1828-dirty #33 Hardware name: Annapurna Labs Alpine V3 EVP (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : __pci_enable_msix_range+0x4e4/0x608 lr : __pci_enable_msix_range+0x498/0x608 sp : ffffff80117db700 x29: ffffff80117db700 x28: 0000000000000001 x27: 0000000000000001 x26: 0000000000000000 x25: ffffffd3e9d8c0b0 x24: 0000000000000000 x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000001 x20: 0000000000000000 x19: ffffffd3e9d8c000 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000000 x15: ffffff80116496c8 x14: ffffffd3e9844503 x13: ffffffd3e9844502 x12: 0000000000000038 x11: ffffffffffffff00 x10: 0000000000000040 x9 : ffffff801165e270 x8 : ffffff801165e268 x7 : 0000000000000002 x6 : 00000000000000b2 x5 : ffffffd3e9d8c2c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffffd3e9844680 Kernel panic - not syncing: Asynchronous SError Interrupt CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-Jonny-14847-ge76f1d4a1828-dirty #33 Hardware name: Annapurna Labs Alpine V3 EVP (DT) Call trace: dump_backtrace+0x0/0x140 show_stack+0x14/0x20 dump_stack+0xa8/0xcc panic+0x140/0x334 nmi_panic+0x6c/0x70 arm64_serror_panic+0x74/0x88 __pte_error+0x0/0x28 el1_error+0x84/0xf8 __pci_enable_msix_range+0x4e4/0x608 pci_alloc_irq_vectors_affinity+0xdc/0x150 pcie_port_device_register+0x2b8/0x4e0 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 Signed-off-by: Lorenzo Pieralisi 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 e96c03b4e494..44524d351a26 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -2925,6 +2925,24 @@ 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 */ /* -- 2.20.1