ATA failure regression

[Shah, Nehal-bakulchandra]

Hi Jiang,

Currently I am working on AMD future platform.  I am hitting the same bug of ATA Failure Regression reported in past.
(https://patchwork.kernel.org/patch/6875661/) or http://lkml.iu.edu/hypermail/linux/kernel/1507.3/01961.html

I am newbie to this and because of this Ubuntu  16.04 is not booting. If disable IOMMU and MSI obviously it works but that is not solution. Even when I bisected it boiled to same place which was mentioned 
in past discussion.

Now my question is there anything required to be done for this future platform in order to make above patch working because it is already present in Ubuntu 16.04 kernel i.e. 4.4 kernel.

Please help me to debug this issue.

Looking forward to hear from you.

Thanks and Regards
Nehal Shah