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

[Bagas Sanjaya]

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:

> 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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