I am currently still investigating and was going to of course reedit things to reflect all the new information. The first post included one problem that was fixed with a firmware swap. The next posts I made here included a lot of new stuff. Hope that makes sense, I didn't want to confuse anyone with misinformation, so I deleted them for the time being. Bare with me, I'll try to detail the problems I'd listed after the first post. I'm actually a writer and reviewer for Headfonics.com and I wanted to write an article about the DX90 rockbox. There is so little support on it that I felt it to merit an entire tips and tricks/support guide.
The problems included:
1.) Playlist support is immensely stressful and far worse than the Mango version of simply adding or managing playlists. Not sure why the Dynamic playlists even exists, nobody wants it to work that way. It is the a useless feature. In fact, it is probably one of the worst ways to create and manage a playlist on a Dap that I've ever seen. In Mango, there is a nice button front and center for creation of a playlist and it works without fail 100% of the time. On the now playing window, there is a simple button that takes you to an Add to Playlist window. Rockbox has that, but it didn't work for me. Dynamic playlists...adding the entire folder contents over just playing a file one by one is just baffling to me. Its like..why do it simple when you can do it in the most complex way imaginable. Nobody wants the entire contents of the device storage unit added to a "dynamic playlist" and when you swap back to a functional Playlist, if you can even get one working, it erases the entire contents of the dynamic playlist just to play the current one. Why? I've no idea, but it is a feature that needs updating.
I've created an M3U file with foobar and transferred it over to the player. For some reason, Playlists folders don't exist until you manually create one in the system. I've transferred the same playlist in .m3u and m3u8 into the new Playlists folder that appears after you make one manually. They show up in the first menu subset in Playlist Catalogue (which isn't the right spelling for the term in English speaking countries. Catalog is proper, but it doesn't really matter). Upon tapping Playlist Catalogue, you are met with a list of Playlists made via some other software. For example, mine is called Mikes Playlist. I click on it and I am met with a listing of all the files I tossed onto it with the software Foobar2000. When I click on any track inside that, it instantly takes me back to the home screen menu listing, Playlist Catalogue still highlighted. I go to Resume Playback and there "is nothing to resume". I try to navigate to the contents of the player and try to find the other Playlists folder via File > MNT > SDcard > Playlists. My custom playlists all show up there. I click on them and nothing happens except a very fast screen flash of "loading...". A fraction of a second, just long enough to read it. Can't move beyond this section.
Another problem in this Playlist problem section of my rant was actual manual creation and adding of a track. Database > Tracks > whatever song, lets say its a whole new world from Aladdin. Don't judge me. LOL. With the track paused, lets try to create a new playlist. Tap the top right to enter context menu and such opens up for you to view Playlist, Playlist Catalogue, Sound Setting ect ect.
Lets click Playlist and see. Playlist > View Current Playlist, search playlist, save current playlist, ect ect. View Current Playlist from Database > Track is the giant 7000+ track collection dynamic playlist that is my external storage device. Lets try Save Current Playlist, which takes me to a typing screen that says the location for the playlist is mnt>sdcard>playlists/dynamic
This is actually something that is going to save all 7000 tracks to a custom playlist. But, as I've mentioned before, this menu location shows only a "loading..." message that pops up for an instant and you can't actually select any Playlists from this area. This is the wrong place to save the playlist. Playlist Catalogue is the correct place to save a playlist. So this function has no use at all but to be stressful.
Lets go back to the now playing track, tap the top right and enter the context menu ( oh by the way my themes context menu is accessed by tapping the top right, im using iLike ). We are met with Add to Playlist and Add to a New Playlist. Selecting add to a playlist opens up the list of the playlists I've created prior. Selecting one of them leaves me with no confirmation and takes me back to the now playing window. But once again, as i've said...the playlists catalogue doesn't let me select any of the playlists tracks and will take me right back to the home menu. The track does in fact show up in the list though after it is added.
So lets try Adding to a New Playlist. I type out a new name for a new playlist. Click ok and am still not given a confirmation. It takes me back to the now playing window. Again, the submenu it gets added into is that other menu from MNT > SDcard > Playlists. the one we can't actually open.
So at this point, go back to the context menu and click Add to a Playlist via Playlist Catalogue. There is no sight of the most recent Playlist I've just tried to create, but the other m3u playlists show up.
Another method that doesn't do anything correctly is Database > Track and long hold over a track name to Insert into the Current Playlist. You can ONLY insert into the current Playlist and you cannot select any other Playlists to toss that into.
Summed up: Playlists need to be completely redone on Rockbox. I've yet to find a single person online who was successful at getting DX90 Rockbox Playlists to work properly.
2.) The bootloader doesn't even support iBasso Daps. It will not recognize the DX90 if it is plugged in and ready to go, there is also no Ibasso listing in the menu set for supported devices, yet others have said that using the bootloader program to help solve a software issues with the DX90 is something I should try. Well, that literally cannot be done. Rockbox for the DX90 has to be manually installed.
3. ) One of my SD cards just doesn't function with the DX90 for Rockbox. Dual boot into Mango, the SD card works normally. In Rockbox, it doesn't register at all. Formatted to Fat32, scanned for viruses, tried just one track on the card, nothing works and the Rockbox'ed DX90 will not recognize the card in the MNT menu. This SD card works with every other dap I own and is recognized by the PC normally. Fiio x1, X3, CalyxM, Sony and Sansa players, my phone and my dslr. Everything works normally with it. However, on the Rockbox os...nope. No clue why, but I bought another brand SD card and that works normally with it.
4. ) OTG cable > thumb drive/portable hard drive usage will not let me see the battery life of the player. It will just say Charged. Seems like a quick fix option and isn't serious, just annoying. Maybe an OTG option just like Mango has would be great for an update. So that we can use OTG and not have the OS register it as a USB charging cable is plugged in. I'd like to see my battery life on the home and now playing screen, not "charging".
5.) There is no DX90 manual for Rockbox.
6.) There is no uninstall Rockbox option inside the rockbox os. You can't really delete the Rockbox software from the DX90, can you? I'm not sure. Just deleting all the files off of it renders Mango glitchy. It will reboot itself randomly and will not actually shut off, it will just cycle right back on after powering down. This doesn't always happen, but it does happen now and then. After deleting files manually for testing in this article I wanted to write, all of this happened. Installing Rockbox again fixed the issue.
As mentioned, I was going to update this thread with all the information I'd discovered and would have detailed it for everyone. But, I didn't want to say anything at the moment because there was speculation and it was in the form of an angry rant, it came off negative in tone and that wasn't my intent.
I love rockbox, it sounds great and I wanted to showcase it in my own review.