On Tue, Dec 05, 2017 at 05:50:37PM +0800, Dongdong Liu wrote:
> Current code has a bug, switch upstream/downstream port error report
> is disabled.
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
>
> We call aer_probe() for a root port, and it enables AER reporting for
> the root port and any downstream devices:
>
> aer_probe(root port) # only binds to root ports
> aer_enable_rootport
> set_downstream_devices_error_reporting(root, true)
> set_device_error_reporting(root, true)
> pci_enable_pcie_error_reporting
> pcie_capability_set_word(root, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS)
> pci_walk_bus(root->subordinate set_device_error_reporting, true)
> set_device_error_reporting(dev, true)
> pci_enable_pcie_error_reporting
> pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
> PCI_EXP_AER_FLAGS)
>
> We later call pcie_portdrv_probe() for every downstream bridge (it
> matches PCI_CLASS_BRIDGE_PCI devices, then discards any non-PCIe
> devices), and it *disables* AER reporting:
>
> pcie_portdrv_probe(switch port)
> pcie_port_device_register
> get_port_device_capability
> pci_disable_pcie_error_reporting
> pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS)
>
> The result is that we first enable AER for the downstream switch
> ports, then we disable it again.
>
> It does not need to disable AER for upstream/downstream ports as
> AER driver only binds to root ports.
>
> Fixes: 2bd50dd800b5(PCI: PCIe: Disable PCIe port services during port
> initialization)
While you're correcting nits, use the conventional style here:
Fixes: 2bd50dd800b5 ("PCI: PCIe: Disable PCIe port services during port initialization")
all on one line for greppability.
> Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> ---
> drivers/pci/pcie/portdrv_core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index a592103..a0dff44 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -241,7 +241,9 @@ static int get_port_device_capability(struct pci_dev *dev)
> * Disable AER on this port in case it's been enabled by the
> * BIOS (the AER service driver will enable it when necessary).
> */
> - pci_disable_pcie_error_reporting(dev);
> + if ((pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
> + (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM))
> + pci_disable_pcie_error_reporting(dev);
I'm not sure this code is in the right place. This is
get_port_device_capability(); we should be *getting* information, not
*configuring* the device here.
If we're not prepared to handle AER events, I think it's probably
a good idea to disable them, but I'd rather do it in the
pci_init_capabilities() path, e.g., in pci_aer_init().
pciehp is not a capability, but I think we should also move the
disabling of PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE interrupts out
of get_port_device_capability(). Maybe to pci_configure_device()?
I also do not think we should check for upstream/downstream ports. If
we're going to disable AER (and I think that probably does make
sense), we should do it for every device until we're ready to handle
AER events.
> }
> /* VC support */
> if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
> --
> 1.9.1
>