Hi Jianfeng, Am Samstag, 27. April 2024, 09:16:38 CEST schrieb Jianfeng Liu: > Hi Emmanuel, > > On Thu, 18 Apr 2024 16:15:04 +0200, Emmanuel Gil Peyrot wrote: > >- Only expose a single VEPU121, since the driver doesn’t yet support > > exposing them all as a single video node to userspace. > I'm also doing work with the hantro node on rk3588 which has both vdpu > and vepu. Discussions can be found here[1]. If I enable the jpeg encoder > at feb50000, would it cause any side effects if other jpeg encoders in > your patch are enabled? And what's the disadvantage of enabling multi > jpeg endoers in devicetree? the basic problem is that exposing multiple jpeg encoders would require userspace to do the scheduling. Which is bad. I.e. all userspace programms would need to know the existence of all jpeg encoders and then somehow negotiate how to use all of them most efficiently. Think multiple different programs that would need to negotiate to spread across all of them in the best way. Doing this in the kernel, we just expose one encoder (and queue) all programs would just pile onto that one encoder and the kernel then would be on the hook to do the scheduling - which the kernel can do better (with relevant code implemented)
