lkml.org 
[lkml]   [2019]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 4/7] PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port
On Thu, Sep 12, 2019 at 04:00:42PM +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.
>
> 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 <jonnyc@amazon.com>
> Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> ---
> drivers/pci/quirks.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)

I will prepare this series for upstream but I would like to have Bjorn's
ACK before pushing it out since you updated this patch following his
review.

Thanks,
Lorenzo

> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 2e983f2a0ee9..c1077e806291 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
>

\
 
 \ /
  Last update: 2019-09-13 13:29    [W:0.043 / U:17.504 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site