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SubjectRe: [PATCH v3] PCI/AER: Enable reporting for ports enumerated after AER driver registration
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在 2018/10/11 23:57, Keith Busch 写道:
> On Thu, Oct 11, 2018 at 08:26:18AM -0700, Bjorn Helgaas wrote:
>> From: Bjorn Helgaas <bhelgaas@google.com>
>>
>> Previously we enabled AER error reporting only for Switch Ports that were
>> enumerated prior to registering the AER service driver. Switch Ports
>> enumerated after AER driver registration were left with error reporting
>> disabled.
>>
>> A common order, which works correctly, is that we enumerate devices before
>> registering portdrv and the AER driver:
>>
>> - Enumerate all the devices at boot-time
>>
>> - Register portdrv and bind it to all Root Ports and Switch Ports, which
>> disables error reporting for these Ports
>>
>> - Register AER service driver and bind it to all Root Ports, which
>> enables error reporting for the Root Ports and any Switch Ports below
>> them
>>
>> But if we enumerate devices *after* registering portdrv and the AER driver,
>> e.g., if a host bridge driver is loaded as a module, error reporting is not
>> enabled correctly:
>>
>> - Register portdrv and AER driver (this happens at boot-time)
>>
>> - Enumerate a Root Port
>>
>> - Bind portdrv to Root Port, disabling its error reporting
>>
>> - Bind AER service driver to Root Port, enabling error reporting for it
>> and its children (there are no children, since we haven't enumerated
>> them yet)
>>
>> - Enumerate Switch Port below the Root Port
>>
>> - Bind portdrv to Switch Port, disabling its error reporting
>>
>> - AER service driver doesn't bind to Switch Ports, so error reporting
>> remains disabled
>>
>> Hot-adding a Switch fails similarly: error reporting is enabled correctly
>> for the Root Port, but when the Switch is enumerated, the AER service
>> driver doesn't claim it, so there's nothing to enable error reporting for
>> the Switch Ports.
>>
>> Change the AER service driver so it binds to *all* PCIe Ports, including
>> Switch Upstream and Downstream Ports. Enable AER error reporting for all
>> these Ports, but not for any children.
>>
>> Link: https://lore.kernel.org/linux-pci/1536085989-2956-1-git-send-email-jonathan.derrick@intel.com
>> Based-on-patch-by: Jon Derrick <jonathan.derrick@intel.com>
>> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>> ---
>> drivers/pci/pcie/aer.c | 16 +++++++++-------
>> 1 file changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
>> index 90b53abf621d..c40c6607849b 100644
>> --- a/drivers/pci/pcie/aer.c
>> +++ b/drivers/pci/pcie/aer.c
>> @@ -1316,12 +1316,6 @@ static void aer_enable_rootport(struct aer_rpc *rpc)
>> pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
>> pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
>>
>> - /*
>> - * Enable error reporting for the root port device and downstream port
>> - * devices.
>> - */
>> - set_downstream_devices_error_reporting(pdev, true);
>> -
>> /* Enable Root Port's interrupt in response to error messages */
>> pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
>> reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
>> @@ -1378,10 +1372,17 @@ static void aer_remove(struct pcie_device *dev)
>> */
>> static int aer_probe(struct pcie_device *dev)
>> {
>> + struct pci_dev *pdev = dev->port;
>> + int type = pci_pcie_type(pdev);
>> int status;
>> struct aer_rpc *rpc;
>> struct device *device = &dev->device;
>>
>> + if (type == PCI_EXP_TYPE_UPSTREAM || type == PCI_EXP_TYPE_DOWNSTREAM) {
>> + pci_enable_pcie_error_reporting(pdev);
>> + return 0;
>> + }
>
> I think we need to either return an error in this case so that the
> pcie_device won't be eligable for the .remove() callback, or add a
> similiar type check in aer_remove().
>

It seems aer_root_reset() also will be called for downstream port(err.c driver->reset_link(dev)),
but aer_root_reset is only for root port.

static struct pcie_port_service_driver aerdriver = {
.name = "aer",
.port_type = PCIE_ANY_PORT,
.service = PCIE_PORT_SERVICE_AER,

.probe = aer_probe,
.remove = aer_remove,
.reset_link = aer_root_reset,
};

Thanks,
Dongdong
> .
>

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