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When a Root Port or Root Complex Event Collector receives an error Message
e.g., ERR_COR, it sets PCI_ERR_ROOT_COR_RCV in the Root Error Status
register and logs the Requester ID in the Error Source Identification
register. If it receives a second ERR_COR Message before software clears
PCI_ERR_ROOT_COR_RCV, hardware sets PCI_ERR_ROOT_MULTI_COR_RCV and the
Requester ID is lost.
In the following scenario, PCI_ERR_ROOT_MULTI_COR_RCV was never cleared:
- hardware receives ERR_COR message
- hardware sets PCI_ERR_ROOT_COR_RCV
- aer_irq() entered
- aer_irq(): status = pci_read_config_dword(PCI_ERR_ROOT_STATUS)
- aer_irq(): now status == PCI_ERR_ROOT_COR_RCV
- hardware receives second ERR_COR message
- hardware sets PCI_ERR_ROOT_MULTI_COR_RCV
- aer_irq(): pci_write_config_dword(PCI_ERR_ROOT_STATUS, status)
- PCI_ERR_ROOT_COR_RCV is cleared; PCI_ERR_ROOT_MULTI_COR_RCV is set
- aer_irq() entered again
- aer_irq(): status = pci_read_config_dword(PCI_ERR_ROOT_STATUS)
- aer_irq(): now status == PCI_ERR_ROOT_MULTI_COR_RCV
- aer_irq() exits because PCI_ERR_ROOT_COR_RCV not set
- PCI_ERR_ROOT_MULTI_COR_RCV is still set
The same problem occurred with ERR_NONFATAL/ERR_FATAL Messages and
PCI_ERR_ROOT_UNCOR_RCV and PCI_ERR_ROOT_MULTI_UNCOR_RCV.
Fix the problem by queueing an AER event and clearing the Root Error Status
bits when any of these bits are set:
PCI_ERR_ROOT_COR_RCV
PCI_ERR_ROOT_UNCOR_RCV
PCI_ERR_ROOT_MULTI_COR_RCV
PCI_ERR_ROOT_MULTI_UNCOR_RCV
See the bugzilla link for details from Eric about how to reproduce this
problem.
[bhelgaas: commit log, move repro details to bugzilla]
Fixes: e167bfcaa4 ("PCI: aerdrv: remove magical ROOT_ERR_STATUS_MASKS")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215992
Link: https://lore.kernel.org/r/20220418150237.1021519-1-sathyanarayanan.kuppuswamy@linux.intel.com
Reported-by: Eric Badger <ebadger@purestorage.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Linux kernel
============
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