[PATCH 5.4 182/389] PCI/portdrv: Dont disable AER reporting in get_port_device_capability()

Greg Kroah-Hartman
2022-08-23T11:32:40Z

From: Stefan Roese <sr@denx.de>

[ Upstream commit 8795e182b02dc87e343c79e73af6b8b7f9c5e635 ]

AER reporting is currently disabled in the DevCtl registers of all non Root
Port PCIe devices on systems using pcie_ports_native || host->native_aer,
disabling AER completely in such systems. This is because 2bd50dd800b5
("PCI: PCIe: Disable PCIe port services during port initialization"), added
a call to pci_disable_pcie_error_reporting() *after* the AER setup was
completed for the PCIe device tree.

Here a longer analysis about the current status of AER enabling /
disabling upon bootup provided by Bjorn:

pcie_portdrv_probe
pcie_port_device_register
get_port_device_capability
pci_disable_pcie_error_reporting
clear CERE NFERE FERE URRE # <-- disable for RP USP DSP
pcie_device_init
device_register # new AER service device
aer_probe
aer_enable_rootport # RP only
set_downstream_devices_error_reporting
set_device_error_reporting # self (RP)
if (RP || USP || DSP)
pci_enable_pcie_error_reporting
set CERE NFERE FERE URRE # <-- enable for RP
pci_walk_bus
set_device_error_reporting
if (RP || USP || DSP)
pci_enable_pcie_error_reporting
set CERE NFERE FERE URRE # <-- enable for USP DSP

In a typical Root Port -> Endpoint hierarchy, the above:
- Disables Error Reporting for the Root Port,
- Enables Error Reporting for the Root Port,
- Does NOT enable Error Reporting for the Endpoint because it is not a
Root Port or Switch Port.

In a deeper Root Port -> Upstream Switch Port -> Downstream Switch
Port -> Endpoint hierarchy:
- Disables Error Reporting for the Root Port,
- Enables Error Reporting for the Root Port,
- Enables Error Reporting for both Switch Ports,
- Does NOT enable Error Reporting for the Endpoint because it is not a
Root Port or Switch Port,
- Disables Error Reporting for the Switch Ports when pcie_portdrv_probe()
claims them. AER does not re-enable it because these are not Root
Ports.

Remove this call to pci_disable_pcie_error_reporting() from
get_port_device_capability(), leaving the already enabled AER configuration
intact. With this change, AER is enabled in the Root Port and the PCIe
switch upstream and downstream ports. Only the PCIe Endpoints don't have
AER enabled yet. A follow-up patch will take care of this Endpoint
enabling.

Fixes: 2bd50dd800b5 ("PCI: PCIe: Disable PCIe port services during port initialization")
Link: https://lore.kernel.org/r/20220125071820.2247260-3-sr@denx.de
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Yao Hongbo <yaohongbo@linux.alibaba.com>
Cc: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/pcie/portdrv_core.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 8637f6068f9c..066406d6d0ee 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -222,15 +222,8 @@ static int get_port_device_capability(struct pci_dev *dev)

#ifdef CONFIG_PCIEAER
if (dev->aer_cap && pci_aer_available() &&
- (pcie_ports_native || host->native_aer)) {
+ (pcie_ports_native || host->native_aer))
services |= PCIE_PORT_SERVICE_AER;
-
- /*
- * 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);
- }
#endif

/*
--
2.35.1