Re: Conflict between v4l and adi module

[Scott Bronson <bronson@rinspin.com>]

> > Immediately after booting, if I fire up my BT848-based TV
> > tuner, quit, then try to open /dev/js0, [it fails].
> Can you confirm by strace that the open() fails ?

Absolutely:

...
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\210\324"..., 1024) = 1024
fstat64(3, {st_mode=S_IFREG|0755, st_size=1149960, ...}) = 0
old_mmap(NULL, 1166404, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40025000
mprotect(0x40138000, 40004, PROT_NONE)  = 0
old_mmap(0x40138000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x112000) = 0x40138000
old_mmap(0x4013e000, 15428, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x4013e000
close(3)                                = 0
munmap(0x40016000, 59758)               = 0
getpid()                                = 665
open("/dev/js0", O_RDONLY)              = -1 ENODEV (No such device)
write(2, "jstest: No such device\n", 23jstest: No such device
) = 23
_exit(1)                                = ?


>> [after rmmoding and modprobing adi]
> Can you confirm that it actually works as opposed to open() working ?
> Does it produce correct values ?

Yes, open() now works and it also produces correct values.
It will continue to work, even if I use v4l again, until
I reboot.


> Do you know whether this occurs with all joysticks ?

Alas, I don't know.  I'd especially like to know if USB joysticks
work like this.  Maybe somebody else on this list could try to
reproduce the problem.


> Do you use your soundcard the joystick is attached to to play sound from
> the TV card ?

Nope.  It goes to some dedicated $5 computer speakers.  The v4l-based
webcams that also cause this problem don't have any audio either.
That was a good thought, but I'm pretty sure it's not audio related.


> Could you try compiling the joystick drivers into the kernel ?

Sure.  It didn't change anything.  /dev/jso: No such device.  However,
now I can't rmmod and insmod adi to fix it.  :)

	- Scott


> > To summarize, the failure (/dev/js0: No such device) only happens
> > if I use v4l before opening /dev/js0 after booting the computer.
> > Once /dev/js0 is successfully opened, it always works from then on.
> > rmmoding and insmoding adi always resolves the conflict.  Rebooting
> > and then using v4l before opening the joystick always causes it.