Blob vs lima

Does anyone have a feature diff between the GPU blob used by CoreELEC and the upstream Lima driver? My guess is that Lime might be the better choice as the blob doesn’t have atomic modesetting (so I’m esp. interrested to know if Lima does atomic modesetting).

Ask Lima devs?

I was asking here as according to Le Potato Mainline kernel - #2 by cdu13a the devs should know the answer (if they say it’s not feature complete they should have a feature diff at hand, right?).
Anyway, asked on the lima mailing list and that’s the answer:

Not a diff, but a relatively recent update since AFAIK not much has changed since:
https://www.youtube.com/watch?v=ZwTDgn-SKGo

So Lima devs doesn’t seem to have a diff at hand (and I don’t have the time to watch a 40 minute video which probably doesn’t even mention the blob).

Me neither and I don’t even care :rofl:
I doubt we are “there” yet. Probably some more time will have to pass to fully replace the blob.

In the case of a media-player we should not care.
Media player is a rather simple specialist application which either works or doesn’t.

Shoog

I’m sorry but… What? Of course you should care.

But it seems to work on both drivers, so why aren’t you switching to lima/upstream? If you follow the link to the other thread the reason is

It is however not feature complete enough on all supported devices to make a switch to it

So what’s the deal? Do you say you think it’s not feature complete cause you don’t care or is that statement based on facts (read: A feature diff you have at hand) ?

//EDIT: Another reply from the lima mailing list:

I don’t think that feature diff exists.

lima dEQP results are on par with the blob.

Not feature complete means it doesn’t support everything blob does. So why switch from working system to semi-working system? It doesn’t make sense.

So what exactly is not supported? You say that as it would be a fact while it seems like you don’t even know the feature differences between the two drivers. Simply list the missing features of Lima if you know them, that’s all I’m asking for but you’re just talking in circles, doing everything to not give that answer.

No, I don’t know them and I never said I know. But as you could read on a post you linked from this forum the dev who knows this stuff is telling you that it just doesn’t work yet. And you don’t trust him? :yum:

He’s not saying it doesn’t work, he’s telling it’s missing features users would expect. So again: What are these missing features?

That’s not a trusting issue: I want to help getting the missing features ready but I can’t as you (not you in person, you as the whole dev team) seem to be unable to list them.

//EDIT: Do you even realize that I’m an experienced dev, too, knowing guys like Neil Armostrong from BayLibre by hand? I’m also experienced in GPU programming, having contact with a lot of FOSS devs from nVidia, AMD, Intel, BayLibre and so on. Please help me to help you instead of talking in circles. This starts to sound like a kindergarden. Again, in clean words: Please list the missing features you’re talking about so they can be integrated into Lima.

Since the features list is not fully available the only way to find out what is working is to move over to Lima and see what is broken. This is a lot of unnecessary work at this stage. It is observed that those projects which have attempted to move to Lima have encountered problems with supporting all features. Until those projects state feature parity the CE project will not waste its time trying Lima.

The object of the CE project is to provide a feature rich media player, not to break those features by testing experimental software.

If you are a dev and are passionate about this maybe you can join the dev team and developed a branch with Lima support, I am sure such a contribution would be welcome and the team would offer all assistance they could.

Shoog

Thanks a lot for this reply. Yea, I think I might fork CE, trying to integrate Lima. Anyway, at this point in time I will not join the team, so the fork will be unofficial. Am I allowed to link that unofficial fork here for testing purposed?

BTW: Might need some time to create that fork as I’m pretty busy atm but it’s on my todo list. :slight_smile:

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@V10lator
Waiting for the same for testing.

I don’t think that the Lima driver will build against the 3.19 and 4.9 kernels which CE uses. Lima is designed for the 5.x series of kernels, which means that if you want to go for Lima you will also have to bump up to a mainline kernel. There are a whole slew of other driver issues associated with mainline beyond the graphics stack.
This is why it is not a trivial matter for the CE team to attempt to move over to Lima and why a stable mature AMLogic/ARM mainline supported kernel is a pr-requisite. Its a relatively small but dedicated team who develop CE and their priority is making CE the best user experience for the majority of its user base. Anything which compromises CE from been the best media player experience is a no go area. We can look to the LibreElec project for an example of what happens when a move to mainline is attempted before the codebase is mature, LE has not had a usable AMLogic build for 2 years at this stage - because they jumped to soon. The CE team will not copy their example - they have to much respect for their users for that.

Shoog

3 Likes

I get the feeling you are offended in some way but there is no need to be offended at all. Let me try to clear things up…

There is no feature diff because nobody really looked into lima. So that’s the answer. We currently have no interest or time for that. But if you want to help with that it would be welcome.

You are free to create your fork. Your changes can be PR’d if they work and if you want that. Alternatively if you want you can create a community build which will save you some time because then you don’t need to do a rebranding for your own project.

If you want to create a community build you are free to open a dedicated thread and support it on this forum. If you just want to link to your own forked project website you can do this in this thread too. In all cases please release the modified source code so we can pick changes too as per GPL license.
But since you are an experienced dev you already know this.

Ray

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