Am Tue, 29 Mar 2016 18:35:20 -0500 hat Nishanth Menon <nm@xxxxxx> geschrieben: Hi, > >> Right now, I get about 6 - 7 hours of usage with a 6000mAh battery > >> (and everything enabled), whereas I have about 8 hours with a > >> 4400mAh battery (and also everything enabled) on the Pandora. > Unfortunately OMAP5 or DRA7 SoCs are no longer focussed on hand held > world. Sorry, TI exited mobile business some years back - OMAP5 was > one of the causalities. Well, yes, I fully agree with the DRA7, but wasn't the OMAP5 originally planned as mobile processor? When we started, the OMAP5430 was still announced, and AFAIR, it was meant for mobile devices, wasn't it? Sadly it never was released, but the OMAP5432 shouldn't be THAT much worse... > >> In theory, the OMAP5 should use less power for the same tasks the > >> DM3730 or OMAP4 can do, but use more power for more CPU usage > >> (which sounds logical). > Not really logical - comparing A15 vs A8 and completely different > process corners behaviors are not comparable. Yes, I know - but still, the A15 (especially with 28nm) should use less power for the same CPU power as an A8, shouldn't it? Unless something really power hungry is going on in there, but as it was originally planned as mobile CPU... hmm. > >> Right now, it seems the kernel is fixed to 1GHz and 1,5GHz (or > >> 500Mhz and 1GHz on our kernel, as we changed the settings). > I suggest to read the operating conditions Addendum (NDA) for OMAP5 to > better understand what OPPs are actually "expected to be function" - > going out side those discrete points are basically "You are on your > own". Well, trying out lower voltages shouldn't damage the system, I guess, it would probably simply crash. > > Not sure what kind of numbers omap5 should be able to get, but my > > guess is we should reasonably easily get to 500 mW with LCD blanked > > and device idle as listed above. That's what omap4 pandaboard es > > seems to measure at with current mainline kernel, so I don't see why > > omap5 could not do the same. > Lets get somethings out of the way here: OMAP5 is NOT OMAP4. Other > than the technologies that are completely different, there has been > quiet a bit of descopes on OMAP5 Vs previous generation SoCs. > Further, a ton of effort in productizing OMAP3 and 4, which is > completely missing in OMAP5. Almost most of power management as has > been functional during OMAP3/4 has been descoped - making it more > inline with DRA7 is the best hope of moving things forward on OMAP5. True, I know that the software is not as optimized as it was with older systems. That's not something I am too afraid of (unless the software cannot be optimized by others because internal knowledge is required) I would be more afraid if the hardware would be an issue here, but I guess hardwarewise the possibilities to save power should be there (as the OMAP5 was developed BEFORE the complete mobile department basically was shut down) > From TI's perspective, despite a few of us community involved folks, > there is very less interest in investigating all the missing features > on OMAP5 at this point in time. That's nothing new and nothing unexpected for us. I just wanted to find out what the general status is and what could be done to improve it. That said, it might not even be as bad as I thought - I've been using the current Pyra for over 8 hours without a charge now. I didn't do anything demanding (typed some text, created the keyboard layout, etc.), but it was with that unoptimized X server that constantly eats 8% CPU power and with all other stuff (USB Ports, 4G Modem, etc.) still enabled (interrupts also added up to about 8% more CPU power). So we had 16% constant CPU load, everything enabled (also the keyboard LEDs) and the battery worked for over 8 hours. I don't know how long it will still work, as it's not yet calibrated, but that doesn't sound too bad. > > I've added linux-omap, Tero and Nishanth to Cc as they may be able > > to provide some more info. > I suggest using e2e.ti.com for further understanding of capabilities > that can be enabled on OMAP5 - mostly getting to understand what TI is > willing to support. I try my best to keep OMAP5 at least on par with > DRA7 where possible - but that is not really in interest to many folks > though. Thanks, every little bit of help really is appreciated! Once the system is released, I'd gladly pay someone who would work on that - but persons capable of doing that are hard to find, and the question is: Is everything that's needed for an improvement available in the hardware documentation? BTW: How similar is the DRA7 to the OMAP5? I know it SOUNDS very similar on the paper, but is the hardware similar as well? -- Mit freundlichen Grüßen, Michael Mrozek ----------------------- OpenPandora GmbH Geschäftsführer: Michael Mrozek Schäffbräustr. 11 85049 Ingolstadt Deutschland Tel.: 0841 / 990 5548 http://www.openpandora.de/ HRB 4879, Amtsgericht Ingolstadt ----------------------- eMail: mrozek@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
