WizardStan
Mega GP Mania
- Joined
- May 24, 2008
- Messages
- 16,733
Just got an update on the TI Flash demo. DSP acceleration has been enabled. I will now start throwing money for realz at whomever can get DSP to work on the Pandora for this.
I'd be very surprised if it's impossible to (eventually) make the DSP start/stop at will from kernelland. This would then make it possible to only give up the memory for as long as the DSP is actually in use.I keep hearing that the DSP will be pretty near useless, though. Apparently it takes up a large amount of RAM? Our RAM is limited enough as it is. Some say that it will take at least 32MB of RAM, others say it might need as much as 128MB.
Its certainly not useless, just no one has had time to dig into it; any volunteers, step up
jeff
I keep hearing that the DSP will be pretty near useless, though. Apparently it takes up a large amount of RAM? Our RAM is limited enough as it is. Some say that it will take at least 32MB of RAM, others say it might need as much as 128MB.
All I can say is that until it's a no-cost option present on everyone's Pandora it's going to be hard encouraging anyone to use it. It isn't a very good situation.
A no-cost option? Is that even theoretically possible?
*sigh*... Honestly it sounds like no matter what happens with this DSP it'll take quite a while to get any practical use out of it. Oh well. It's still an awesome device, even with its currently-useless DSP.
I think the point is that the DSP maps its address space into a range that is used by physical RAM already .. so the kernel has to be told to mask off that range at boot-time so that the DSP module can use it for shmem-style communication between the DSP and main CPU .. the RAM isn't actually used, its just mapped off.
Seems to me that it would be *possible* to have the kernel module map this address range, and then make it available to apps that want to use it (which aren't going to use the DSP) but this is quite sophisticated and probably would be a bit of work to actually implement ..
Maybe a really killer app use case that's < 16MB needs to be done first, but as far as Pandora developers themselves are concerned it's very chicken and egg.
The tools are around, it's not like we keep the source only to ourselves. If nobody bothers to even compile the DSP modules it's rather unlikely somebody will write code for DSP (the former is a lot easier then the later).I think the most important point is to give developers the tools to use the DSP. There must be an option to choose the amount of RAM reserved for the DSP even if it's only at boot time or with other tricky methods (using a specially formatted SD card, etc.). When that's done, we will see what devs can or cannot do with the DSP.