RE: [EXT] Re: [PATCH v2 0/5] UFS Host Performance Booster (HPB v1.0) driver

[Bean Huo (beanhuo)]

Hi, Christoph
Thanks for your feedback. 

> > To avoid touching the traditional SCSI core, the HPB driver in this
> > series HPB patch chooses to develop under SCSI sub-system layer, and
> > sits the same layer with UFSHCD. At the same time, to minimize changes
> > to UFSHCD driver, the HPB driver submits its HPB READ BUFFER and HPB
> > WRITE BUFFER requests to the scsi
> > device->request_queueu to execute, rather than that directly go
> > device->through
> > raw UPIU request path.
> 
> This feature is completley broken, and rather dangerous due to feeding
> "physical" addresses looked up by the host in.  I do not think we should support
> something that broken in Linux.
>

It Is not plain physical address,  has been encrypted before loading from UFS to
HPB memory, I think we don't worry about its safety.

> Independent of that using two requests in the I/O path is not going to fly either.
> The whole thing seems like an exercise in benchmarketing.

I agree with you. This is my major concern. I have been thinking about HPB implementation in SCSI layer.
That will let SCSI layer manage HPB by calling UFS helper interface. 
If you don't consider UFS HPB is an idiot design,  I want to  change in another version.  Firstly, we really
want to hear your suggestion.
Thanks,

//Bean