[PATCH fpga 8/9] fpga socfpga: Use the scatterlist interface

[atull]

On Wed, 16 Nov 2016, Jason Gunthorpe wrote:

> On Wed, Nov 16, 2016 at 09:45:23AM -0600, atull wrote:
> > > What is the point of this if write_init gets a copy of the buffer -
> > > what is that supposed to be?
> > 
> > Sometimes write_init needs to look at the header of the image.
> > You can see that in the socfpga-a10.c (on linux-next/master)
> 
> I know what it is for, I'm asking what should it be if we are calling
> write_init multiple times.
> 
> It feels like the driver needs to indicate the header length it wants
> to inspect and the core core needs to make that much of the bitstream
> available to write_init() before calling write().
> 
> Is that what you were thinking?

That would make sense.  socfpga-a10.c requires a certain amount
of header in write_init, but the current API didn't have a way
for socfgpa-a10.c to specify that to fpga-mgr.c core.  Should
probably happen during registration.  If you have an idea about
that, that's good, otherwise we'll get back to that separately.

> 
> > at this stuff, this is coming at a busy time).  My point there
> > was that there was code that needed to go into the core so that
> > the ICE40 and the cyclone spi driver that are on the mailing
> > list won't have to have the same workaround that you were
> > adding to the socfpga.c driver.
> 
> Sure, that is easy for write() - not clear on write_init sematics?
> I will send a revised series.
> 
> I'd also like to close on the zynq bitfile verification patch, did you
> have any comments on that?

I think Joshua had some comments.  Besides that, I'm ok with that
patch.

Alan

> 
> Jason
>