Re: [XEN PATCH v1] xen/arm : Add support for SMMUv3 driver

[Julien Grall <julien@xxxxxxx>]

On 30/10/2020 09:45, Rahul Singh wrote:
> Hello Julien,
>
> > On 30 Oct 2020, at 9:21 am, Julien Grall <julien@xxxxxxx> wrote:
> >
> > Hi,
> >
> > On 30/10/2020 08:46, Rahul Singh wrote:
> > > Ok Yes when I ported the driver I port the command queue operation from the 
> > > previous commit where atomic operations is not used and rest all the code is 
> > > from the latest code. I will again make sure that any bug that is fixed in 
> > > Linux should be fixed in XEN also.
> > I would like to seek some clarifications on the code because there seem to be 
> > conflicting information provided in this thread.
> >
> > The patch (the baseline commit is provided) and the discussion with Bertrand 
> > suggests that you took a snapshot of the code last year and adapted for Xen.
> >
> > However, here you suggest that you took an hybrid approach where part of the 
> > code is based from last year and other part is based from the latest code (I 
> > assume v5.9).
> >
> > So can you please clarify?
> >
> > Cheers,
> Approach I took is to first merge the code  from the commit ( Jul 2, 2019 
> 7c288a5b27934281d9ea8b5807bc727268b7001a ) the snapshot before atomic operation 
> is used in SMMUv3 code for command queue operations.
>
> After that I fixed  the other code( not related to command queue operations.)  
> from the latest code so that no bug is introduced in XEN because of using the 
> last year commit.
Ok. That was definitely not clear from the commit message. Please make 
this clearer in the commit message.
Anway, it means we need to do a full review of the code (rather than a 
light one) because of the hybrid model.
I am still a bit puzzle to why it would require almost of a restart of 
the implementation in order to sync the latest code. Does it imply that 
you are mostly using the old code?
Cheers,

--
Julien Grall