Convert latents_ubyte to 8-bit unsigned int before converting to CPU

[shenanigansd]

Hello, not sure if this is the best solution, but looks like it fixes the issue described in #3539 for most people, me included, so I'll go ahead and submit this PR.
Fixes #3539

[traugdor]

it indeed resolves #3539. This has been an on-going issue for AMD device users and needs to be addressed ASAP.

[comfyanonymous]

can you make this only apply on directml?

[Kosinkadink]

A code snippet to help make the directml check: in comfy.model_management.py, there is a variable called directml_enabled. As the name implies, if it's True, directml was enabled on startup.

import comfy.model_management

if comfy.model_management.directml_enabled:
    # do directml_enabled thing...

[traugdor]

I was actually going to suggest this in the morning after sleeping on it, but I see you beat me to it.

[shenanigansd]

Sorry, I'm new here and I don't understand. I'm happy to update the PR, but I'm not understanding where to insert the provided snippet. Is it just this? (plus the import)

[Kosinkadink]

@shenanigansd If you're stuck making that change, I can make a contribution to your PR so that we can get this change through.

[shenanigansd]

Sorry, I just got busy at work and haven't had a chance to circle back yet. I think I've made the requested changes correctly now in 79c526f. If I messed up, please go ahead and make the correct updates @Kosinkadink.

[Kosinkadink]

No worries, just wanted to make sure this PR doesn't go stale given a lot of AMD peeps may be impacted by this. The change looks good to me, I don't have an AMD gpu at the moment to test it on, but assuming this works on your machine, I think this can get merged in very soon.