> Hi,
> 
> after updating to 5.2 the wi-fi driver stopped working when the iommu
> is enabled.
> It fails to list the available wi-fi networks or connect to a known one.
> booting with amd_iommu=off works around the problem.
> The staging version in 5.1 and older worked OK with the iommu enabled
> 
> The device is:
> 04:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8822BE
> 802.11a/b/g/n/ac WiFi adapter
> 
> I do see an IOMMU error in dmesg, but the originating device does not
> match the nics pci location:
> Jul 08 15:03:14 host kernel: rtw_pci 0000:04:00.0: start vif
> xx:xx:xx:xx:xx:xx on port 0
> Jul 08 15:03:14 host kernel: iommu ivhd0: AMD-Vi: Event logged
> [INVALID_DEVICE_REQUEST device=00:00.1 pasid=0x00000
> address=0xfffffffdf8140200 flags=0x0a00]
> Jul 08 15:03:14 host kernel: rtw_pci 0000:04:00.0: stop vif
> xx:xx:xx:xx:xx:xx on port 0
> Jul 08 15:03:14 host NetworkManager[790]: <info>  [1562612594.8992]
> device (wlp4s0): set-hw-addr: set MAC address to yy:yy:yy:yy:yy:yy
> (scanning)
> Jul 08 15:03:15 host kernel: rtw_pci 0000:04:00.0: start vif
> yy:yy:yy:yy:yy:yy on port 0
> 
> let me know if I should provide any further info.
> thanks,
> Jan
> 


Hi,

I am not sure if enabling MSI interrupt is going to help.
You can try the patch attached, if it works, I will send it to upstream.
Thanks

Yan-Hsuan