On Wed, May 19, 2021 at 09:42:42AM -0700, Jianxiong Gao wrote:

On Wed, May 19, 2021 at 1:11 AM Greg KH [off-list ref] wrote:

quoted

I still fail to understand why you can not just use the 5.10.y kernel or
newer.  What is preventing you from doing this if you wish to use this
type of hardware?  This is not a "regression" in that the 5.4.y kernel
has never worked with this hardware before, it feels like a new feature.

NVMe + SWIOTLB is not a new feature. From my understanding it should
be supported by 5.4.y kernel correctly. Currently without the patch, any
NVMe device (along with some other devices that relies on offset to
work correctly), could be broken if the SWIOTLB is used on a 5.4.y kernel.

Then do not do that, as obviously it never worked without your fixes, so
this isn't a "regression".

And again, why can you not just use 5.10.y?

thanks,

greg k-h