[PATCH] PCI : Fix pcie_flag_reg in set_pcie_port_type

From: Gowthami Thiagarajan
Date: Mon Nov 04 2024 - 04:16:56 EST


The port type in set_pcie_port_type is not set proper when an invalid
topology is detected. Since the port type was not set proper, the child's
extended config space becomes inaccessible.

[ 70.440438] pci 0002:00:00.0: [177d:a002] type 01 class 0x060401
[ 70.463056] pci 0002:00:00.0: reg 0x38: [mem 0x600000000000-0x6000000007ff pref]
[ 71.806936] pci 0002:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 71.906688] pci (null): claims to be downstream port but is acting as upstream port, correcting type
[ 71.916138] pci 0002:01:00.0: [177d:a002] type 01 class 0x060401
[ 71.935982] pci 0002:01:00.0: reg 0x38: [mem 0x600000000000-0x6000000007ff pref]
[ 72.134703] pci 0002:01:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 72.198956] pci_bus 0002:02: extended config space not accessible
.......
[ 83.762956] pci_bus 0002:03: extended config space not accessible
[ 83.792530] pci 0002:03:00.0: [177d:a065] type 00 class 0x020000
[ 83.813188] pci 0002:03:00.0: reg 0x10: [mem 0x600000000000-0x6003ffffffff 64bit pref]
[ 83.832490] pci 0002:03:00.0: reg 0x18: [mem 0x600000000000-0x600003ffffff 64bit pref]
[ 83.848507] pci 0002:03:00.0: reg 0x20: [mem 0x600000000000-0x60000000ffff 64bit pref]
[ 83.935564] pci_bus 0002:03: busn_res: [bus 03-ff] end is updated to 03
[ 83.998804] pci_bus 0002:04: extended config space not accessible
[ 84.025026] pci 0002:04:00.0: [177d:a063] type 00 class 0x020000
[ 84.055298] pci 0002:04:00.0: reg 0x18: [mem 0x600000000000-0x600003ffffff 64bit pref]
[ 84.147582] pci_bus 0002:04: busn_res: [bus 04-ff] end is updated to 04
[ 84.202778] pci_bus 0002:05: extended config space not accessible
[ 84.228684] pci 0002:05:00.0: [177d:a063] type 00 class 0x020000
[ 84.258887] pci 0002:05:00.0: reg 0x18: [mem 0x600000000000-0x600003ffffff 64bit pref]

Signed-off-by: Gowthami Thiagarajan <gthiagarajan@xxxxxxxxxxx>
---
drivers/pci/probe.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4f68414c3086..263ec21451d9 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1596,7 +1596,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
if (pcie_downstream_port(parent)) {
pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n");
pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
- pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM;
+ pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM << 4;
}
} else if (type == PCI_EXP_TYPE_UPSTREAM) {
/*
@@ -1607,7 +1607,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) {
pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n");
pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
- pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM;
+ pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM << 4;
}
}
}
--
2.25.1