qorron / discover_bugs

a Documentation of Bugs on Volkswagen's Discover series of infotainment systems.

Discover Bugs

a Documentation of Bugs on Volkswagen's Discover series of infotainment systems.

for some of them I came up with a workaround that will be documented as well.

discover_bugs's Issues

The "Shania Twain" Bug. aka last song played is lost and first song is played

as the title explains, last song and position of playback is lost in about 50% when the unit is turned back on.
if that happens the first song on the second SD-card is played. in my case that was 'Ka-Ching!' by Shania Twain, hence the name of that bug.

annoyance factor: high (if you happen to listen to audio books with files about 45min or more in length while driving long distances on the highway, this changes to: agony!)

workaround:
every time I stop and leave the car, even for a short break, I took a picture of the playback screen indicating the current file and position of playback with my phone. I ended up having hundreds of pictures.

Files-structure Cache is easily broken and has no easy way to fix

the defect roots in the fact that they scan the whole FS to present a directory tree structure to the user.
I'm unable to draw a picture of the whole extent of that bug because a pattern has yet to emerge.
what has been observed so far:

have one corrupt file in a directory (FS is ok, just the file is truncated)
dp2 won't play it, marking it with an exclamation mark.
back at the PC, fix, the file (FS is still ok)
dp2 shows formerly corrupt file twice, both with exclamation marks, refuses to play either of them.
rename containing dir
dp2 shows all ok plays all.
rename the dir back
dp2 shows the dir twice, entering either of them shows a normal list of files, but every file is played twice before the next file is played.

e.g. what I see:

dir1---file1.ogg
     |-file2.ogg
     |-file3.ogg
dir1---file1.ogg
     |-file2.ogg
     |-file3.ogg

what dp2 plays:

file1.ogg
file1.ogg
file2.ogg
file2.ogg
file3.ogg
file3.ogg

the FS has been repeatedly checked and wasn't corrupted at any time during this experiment.

a file-system already is a database to organize files hierarchically. almost all of then do their job well.
so I ask myself 2 questions:

1. why reinvent a perfectly good wheel?
2. why replace something that works with something that doesn't?

Limit of about 10.000 files per sd-card/flash drive

now this is annoying:
even the first discover pro models supported the SDXC standard, meaning it allows for cards with up to 2TB of storage.

however, they decided that 10.000 files are enough (about 60gig, using mostly mp3 and ogg).
files beyond that limit are simply not available for playback.
none of the cheaper models (discover media, composition media,..) suffer from this defect.
the reason for this is that they scan the whole card and practically keep their own copy of the filesystem structure. this copy is used to browse the fileystem.
while the first version used a depth first search, meaning that at some point the top level directories where empty, the second model switched to a breadth-first search which made matters even worse.
now files are only visible to a certain level, making it impossible to tell is a desired file is available.

workaround:
I have written a small script that tries to divide your music onto several sd-cards.
please find it here:
https://github.com/qorron/discover_bugs/blob/master/scripts/divide.pl

system is muted after power on

in about 2 out of 10 cases, the system is muted when powered on.
changing the volume has no effect (buttons on the wheel and touch areas on the unit alike).
the volume bar moves, but no sound is audible.
the media appears to be playing, seconds increase and so on.
driving directions (e.g. "turn left now") are muted as well.
sound effects in the gui can be heard however if they are enabled.

workaround:
change to radio and back.