Re: [PATCH v2 2/7] media: chips-media: wave5: Improve performance of decoder

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

Hi,

Le jeudi 05 juin 2025 à 04:50 +0000, jackson.lee a écrit :
> > So my question is, is there a way to know, at CMD_STOP call, that the HW
> > has gone idle, and that no more events will allow handling the EOS case?
> > 
> > Nicolas
> 
> 
> Thanks for your reply.	
> 
> Now there is only one thing to know if there is more events or not to handle the EOS case.
> It is that driver sends DEC_PIC command to VPU continuously until display index is -2(it means EOS) from VPU.
> VPU should trigger interrupts to get display index from the finish_decode function.
> So we have to run device_run to send DEC_PIC command.

What don't want to see is a loop where we do:

	device_run()
		finish_job()
			device_run()
				finish_job()
					....

What I see now, is that we simply bang on the trigger until it completes, which
is very wasteful in power and CPU time. In your next version, make sure to
find a mitigation to that active loop, and document it please.

Nicolas