Re: [PATCH v4 0/7] VSP1: Display writeback support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Brian,

On Thu, Feb 21, 2019 at 01:44:56PM +0000, Brian Starkey wrote:
> On Thu, Feb 21, 2019 at 02:23:10PM +0200, Laurent Pinchart wrote:
> > On Thu, Feb 21, 2019 at 12:19:13PM +0000, Brian Starkey wrote:
> 
> [snip]
> 
> >> I used a pre-existing internal tool which does exactly that.
> > 
> > Any hope of sharing the sources ?
> 
> Not in a timescale or form which would be useful to you. I'm convinced
> people only ask questions like this to make us look like Bad Guys.

I didn't have big hopes, but it was a honest question.

> Opening everything up is a process, and it's going to take us time.
> Sure we could be doing better, but I also think there's a lot of
> people who do worse.

No question that ARM is neither the worst nor the best. I also value
your and the other graphics developer's efforts more than I value ARM's
open-source policy, as you are fighting against company policies to
drive open-source.

> >> I appreciate that we don't have upstream tooling for writeback. As you
> >> say, it's a young API (well, not by date, but certainly by usage).
> >> 
> >> I also do appreciate you taking the time to consider it, identifying
> >> issues which we did not, and for fixing them. The only way it stops
> >> being a young API, with bugs and no tooling, is if people adopt it.
> > 
> > If the developers who initially pushed the API upstream without an
> > open-source test tool could spend a bit of time on this issue, I'm sure
> > it would help too :-)
> 
> No one suggested a test test tool before. In fact, the DRM subsystem
> explicitly requires that features land with something that isn't only
> a test tool, hence why we did drm_hwcomposer.
> 
> That said, yes, we should be trying harder to get the igts landed. I
> personally think igts are far more useful than a random example C
> file, but I guess opinions differ.

I think both are useful, for different purposes. Automated test cases
are very valuable to test for compliance and catch regressions, while a
manualy tool is very valuable during development.

-- 
Regards,

Laurent Pinchart