On Mon, 2019-08-19 at 19:23 +0100, Andrew Murray wrote: > On Tue, Jul 23, 2019 at 12:25:29PM +0300, Jonathan Chocron wrote: > > The Root Port (identified by [1c36:0032]) doesn't support MSI-X. On > > some > > Shouldn't this read [1c36:0031]? > Indeed. Thanks for catching this.
> > > 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: > > > > [ 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 > > > > Signed-off-by: Jonathan Chocron <jon...@amazon.com> > > Reviewed-by: Gustavo Pimentel <gustavo.pimen...@synopsys.com> > > --- > > drivers/pci/quirks.c | 15 +++++++++++++++ > > 1 file changed, 15 insertions(+) > > > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > > index 23672680dba7..11f843aa96b3 100644 > > --- a/drivers/pci/quirks.c > > +++ b/drivers/pci/quirks.c > > @@ -2925,6 +2925,21 @@ > > 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. > > + * > > + * 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-X\n"); > > This will disable both MSI and MSI-X support - is this really the > intention > here? Do the root ports support MSI and legacy, or just legacy? > The HW should support MSI, but we currently don't have a use case for it so it hasn't been tested and therefore we are okay with disabling it. For future knowledge, how can just MSI-X be disabled? I see that in pcie_port_enable_irq_vec(), the pcieport driver calls pci_alloc_irq_vectors() with PCI_IRQ_MSIX | PCI_IRQ_MSI. And internally, both __pci_enable_msix_range() and __pci_enable_msi_range() use pci_msi_supported() which doesn't differentiate between MSI and MSI-x. > Thanks, > > Andrew Murray > > > +} > > +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 > >