On Fri, Jan 04, 2013 at 01:25:06PM -0700, Stephen Warren wrote:
On 01/04/2013 03:09 AM, Terje Bergström wrote: ...
I think we have now two ways to go forward with cons and pros:
- Keep host1x and tegra-drm as separate driver
- Code almost done
- we need dummy device and dummy driver
- extra code and API when host1x creates dummy device and its passed
to tegra-drm
Just to play devil's advocate:
I suspect that's only a few lines of code.
- tegra-drm device would need to be a child of host1x device. Having
virtual and real devices as host1x children sounds weird.
And I doubt that would cause problems.
- Merge host1x and tegra-drm into one module. drm is a subcomponent,
and whatever other personalities we wish would also be subcomponents of host1x. host1x calls tegra-drm directly to handle preparation for drm initialization. As they're in the same module, circular dependency is ok.
- Simpler conceptually (no dummy device/driver)
- Less code
- Proposal doesn't yet exist
But that said, I agree this approach would be very reasonable; it seems to me that host1x really is the main HW behind a DRM driver or a V4L2 driver or ... As such, it seems quite reasonable for a single struct device to exist that represents host1x, and for the driver for that device to register both a DRM and a V4L2 driver etc. The code could physically be organized into separate modules, and under different Kconfig options for configurability etc.
But either way, I'll let you (Thierry and Terje) work out which way to go.
Sorry for not getting back to you on this earlier. I just remembered this thread when I saw Terje's latest patch series.
I agree that having everything in one location will make things a lot easier, even if it means we have to add the tegra-drm driver to a new location. In the long run I think this will pay off, though.
That said, I see that Terje has chosen this approach in his latest series, so it's all good.
Thierry