AGPTEK Rocker

[Milardo]

I see this on the main page

"    e85a3ba: Agptek rocker: do not update display when not active "

What does that patch do?

I updated to that version but the I can still see the display under a flashlight and the everything is still moving like play time indicator, etc.

[wodz]

Finally I found some time to mess with framebuffer and I have bad news. You can blank fb (either by writing 1 to /sys/class/graphics/fb0/blank or by calling ioctl(fd, FBIOBLANK, FB_BLANK_POWERDOWN)) BUT when you unblank (writing 0 to  /sys/class/graphics/fb0/blank or calling ioctl(fd, FBIOBLANK, FB_BLANK_UNBLANK)) lcd does not update anymore. Writes to mmaped fb are successful, you can read back updated fb content but apparently DMA is not fired and data are not flushed to lcd. I tried different combinations and I am unable to make it work. So either agptek's fb driver is terribly broke or I miss something basic.

[Markfm]

Wodz, have you heard anything about bluetooth for the Rocker recently?

[wodz]

If by 'heard' you mean 'have you implemented BT support in rockbox' then answer is no.

[Markfm]

Thanks!  I wasn't sure if I'd missed something since your post on it in Dec.

[Pingouin]

Finally I found some time to mess with framebuffer and I have bad news...

Doh! Well, thanks anyway for trying.

[wodz]

After some digging and reverse engineering kernel running on Agptek I am able to revive lcd after blanking. Lcd driver is terribly broken as it doesn't reenable DMA when unblanking. There is undocumented ioctl however which enables DMA transfers to lcd as side effect. I'll try to post build for testing within few days.

[Chronon]

Nice work, wodz!

[Pingouin]

Thanks wodz!
The question will then be: does all your hard work actually saves any battery?
And the other question: why didn't AGPtek try to fix their LCD driver rather than implement a software dirty hack to mitigate it! Although it doesn't seem it's actually AGPtek soft/hardware anyway, but someone must have been spending some time doing the same thing you did and would have had the opportunity to point out the driver problem to get it fixed. Unless they decided that the quick and dirty hack was more cost effective.

[wodz]

Driver comes from Ingenic itself. See https://github.com/Ingenic-community/kernel-xburst-bsp for reference. Software for Agptek was developed by Fiio I believe. Based on my RE work on original software I believe they do not blank lcd and hence they don't trigger this bug (I may be wrong of course but I can't trace any ioctl or direct write to sysfs associated with locking screen in OF). I think OF writes all black screen, turnes off backlight and then stops writing to lcd.

The only way to know if blanking saves any energy is to banchmark it.

[Gomas]

Amazing work you're doing right there wodz. If you want us to give a hand with testing, just say it so we can give it a few benches.

[wodz]

Please test and drop feedback. I am interested if this lcd blanking is working on T6 and Rocker v2. If it works, please battery bench this build and compare to HEAD version so we can judge if this saves anything.

https://drive.google.com/open?id=1cDyTcAVjce50NuHQxRO3SQy-006OVS0I

[elakir]

Please test and drop feedback. I am interested if this lcd blanking is working on T6 and Rocker v2. If it works, please battery bench this build and compare to HEAD version so we can judge if this saves anything.
https://drive.google.com/open?id=1cDyTcAVjce50NuHQxRO3SQy-006OVS0I

Big thanks wodz!

Benjie T6(no bluetooth)
I still see color text on the screen when I look at it at an angle(with the presence of external lighting). However, no text lines scrolled.
Now I will charge the player and make battery_bench

Up.2019-06-18: battery_bench is ready

[wodz]

The difference is insignifican't unfortunately.

[coacharnold]

Hi .....  without spending a lot of time looking this up .... can someone tell me, is this the player :

AGPTEK ROCKER Bluetooth 4.0 MP3 Player, High Resolution Lossless Music Player for Audiophile(up to 256GB), black /sliver

And does blue tooth work with rock box?  Is there a wiki for the install process??

I see it on wallmart's site for 50$,   I'll buy one today if it works.

Thank you

Tim