[hns-1126]net: hns3: fix interrupt clearing error for VF

[Fred Kimmy]

"[Bug Description]
Currently, VF driver has two kinds of interrupts, reset & CMDQ RX.
According to the UM, each interrupt should be cleared by write 0
to the corresponding bit, but the implementation is write 0 to the
whole register in fact, it will clear other interrupt at the same
time, then the VF will loss the interrupt.

[Steps to Reproduce]
1.load PF&VF driver
2.echo ""1"" > /sys/class/net/${LocalNetwork}/device/sriov_numvfs
3.check message by dmesg command

[Actual Results]
Add VF failed

[Expected Results]
Add VF successfullly

[Reproducibility]
Inevitably

[Additional information]
Hardware: D06 ES
Firmware: NA
Kernel: NA

[Resolution]
This patch fixes it, also, adds a new register for reading the interrupt
status according to hardware user manual."

net: hns3: fix interrupt clearing error for VF
net: hns3: Add HNS3 VF HCL(Hardware Compatibility Layer) Support
net: hns3: add reset handling for VF when doing Core/Global/IMP reset

[Ike Panhc (ikepanhc)]

commit 130509213baeb3cada40c19dd87341a6787f8b23
Author: Huazhong Tan <email address hidden>
Date: Fri Aug 9 10:31:08 2019 +0800

    net: hns3: fix interrupt clearing error for VF

This patch fixes

    Fixes: e2cb1dec9779 ("net: hns3: Add HNS3 VF HCL(Hardware Compatibility Layer) Support")
    Fixes: b90fcc5bd904 ("net: hns3: add reset handling for VF when doing Core/Global/IMP reset")

which been introduced while v5.0

I will see if we shall backport this fix for v5.3

[Andrew Cloke (andrew-cloke)]

19.04 is now EOL.

[Ike Panhc (ikepanhc)]

Can't clean cherry-picked for eoan/master-next.