Fwd: The PCIe AER error flood between PCIe bridge and Realtek's RTL8723BE makes system hang

Hi,

I notice a bug report on Bugzilla [1]. Quoting from it:

We have an ASUS X555UQ laptop equipped with Intel i7-6500U CPU and Realtek RTL8723BE PCIe Wireless adapter.

We tested it with kernel 6.6.  System keeps showing AER error message flood, even hangs up, until rtl8723be's ASPM is disabled.

kernel: pcieport 0000:00:1c.5: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID)
kernel: pcieport 0000:00:1c.5:   device [8086:9d15] error status/mask=00000001/00002000
kernel: pcieport 0000:00:1c.5:    [ 0] RxErr                  (First)
kernel: pcieport 0000:00:1c.5: AER: Corrected error received: 0000:00:1c.5
kernel: pcieport 0000:00:1c.5: AER: can't find device of ID00e5
kernel: pcieport 0000:00:1c.5: AER: Corrected error received: 0000:00:1c.5
kernel: pcieport 0000:00:1c.5: AER: can't find device of ID00e5
kernel: pcieport 0000:00:1c.5: AER: Multiple Corrected error received: 0000:00:1c.5
kernel: pcieport 0000:00:1c.5: AER: can't find device of ID00e5

Here is the PCI tree:
$ lspci -tv
-[0000:00]-+-00.0  Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Host Bridge/DRAM Registers
           +-02.0  Intel Corporation Skylake GT2 [HD Graphics 520]
           +-04.0  Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem
           +-14.0  Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller
           +-14.2  Intel Corporation Sunrise Point-LP Thermal subsystem
           +-15.0  Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0
           +-15.1  Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1
           +-16.0  Intel Corporation Sunrise Point-LP CSME HECI #1
           +-17.0  Intel Corporation Sunrise Point-LP SATA Controller [AHCI mode]
           +-1c.0-[01]----00.0  NVIDIA Corporation GM108M [GeForce 940MX]
           +-1c.4-[02]----00.0  Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
           +-1c.5-[03]----00.0  Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
           +-1f.0  Intel Corporation Sunrise Point-LP LPC Controller
           +-1f.2  Intel Corporation Sunrise Point-LP PMC
           +-1f.3  Intel Corporation Sunrise Point-LP HD Audio
           \-1f.4  Intel Corporation Sunrise Point-LP SMBus

And then the reporter found that it was ASPM bug:

quoted hunk

Notice a long time ago discussion mail: Dmesg filled with "AER: Corrected error received" [1]

So, I force write 1 to clear Receiver Error Status bit of Correctable Error Status Register, like

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 9c8fd69ae5ad..39faedd2ec8e 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c

@@ -1141,8 +1160,9 @@ static void aer_isr_one_error(struct aer_rpc *rpc,
                        e_info.multi_error_valid = 0;
                aer_print_port_info(pdev, &e_info);
 
-               if (find_source_device(pdev, &e_info))
-                       aer_process_err_devices(&e_info);
+               //if (find_source_device(pdev, &e_info))
+               //      aer_process_err_devices(&e_info);
+               pci_write_config_dword(pdev, pdev->aer_cap + PCI_ERR_COR_STATUS, 0x1);
        }
 
        if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {

Then, system should clear the error right away.  However, system still get the AER flood ...

Seems that we still have to disable rtl8723be's ASPM.

See Bugzilla for the full thread and attached full kernel logs.

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=218127

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