[PATCH v4 7/8] PCI/ERR: Remove redundant clearing of AER register in pcie_do_recovery()

From: Naveen Naidu
Date: Tue Oct 05 2021 - 13:21:37 EST


pcie_do_recovery() is shared across the following paths:
- ACPI APEI
- Native AER path
- EDR
- DPC

ACPI APEI
==========

ghes_handle_aer()
aer_recover_queue()
kfifo_in_spinlocked(aer_recover_ring)

aer_recover_work_func()
while (kfifo_get(aer_recover_ring))
pcie_do_recovery()

In this path the system firmware clears the AER registers before
handing off the record to the OS in ghes_handle_aer()

Native AER
==========

aer_irq()
aer_add_err_devices_to_queue()
kfifo_put(&rpc->aer_fifo, *e_dev)
clear_error_source_aer_registers() <---- AER registers are cleard

aer_isr()
aer_isr_one_error()
handle_error_source()
pcie_do_recovery()

The AER registers are cleared during the handling of IRQ, i.e before we
the recovery starts.

DPC
=====

dpc_handler()
dpc_process_error()
pci_aer_clear_status() <---- AER registers are cleared
pcie_do_recovery()

EDR
====

edr_handle_event()
dpc_process_error()
pci_aer_raw_clear_status() <---- AER registers are cleared
pcie_do_recovery()

In all the above paths, the AER registers are cleared before
pcie_do_recovery(). The non fatal status AER registers are again cleared
in pcie_do_recovery(). This is redundant.

Remove redundant clearing of AER register in pcie_do_recovery()

Signed-off-by: Naveen Naidu <naveennaidu479@xxxxxxxxx>
---
drivers/pci/pcie/err.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index b576aa890c76..fe04b0ae22f4 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -231,14 +231,11 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,

/*
* If we have native control of AER, clear error status in the device
- * that detected the error. If the platform retained control of AER,
- * it is responsible for clearing this status. In that case, the
- * signaling device may not even be visible to the OS.
+ * that detected the error.
*/
- if (host->native_aer || pcie_ports_native) {
+ if (host->native_aer || pcie_ports_native)
pcie_clear_device_status(dev);
- pci_aer_clear_nonfatal_status(dev);
- }
+
pci_info(bridge, "device recovery successful\n");
return status;

--
2.25.1