I have an es1371 based sound card (SoundBlaster128, I believe), and my [Linux Kernel] 2.4.x joystick ride has been kinda bumpy. Some kernels would detect the joystick port, others wouldn't.
I really like having a working joystick so I can play emulated games :)
So tonight I decided that I was gonna get it working again. I inserted the es1371 module, and noticed that it read:
es1371: features: joystick 0x0
That's not right. I knew my port was somewhere in the
0x2**range. If I gave it
joystick=0x200, my machine would freeze right away when trying to load the joystick module. (
0x200was the previous value I remembered).
So I looked in
/usr/src/linux/drivers/sound/es1371.c, and note that the
0x2**range is not really the address, but the offset. Ok, so far nothing spectacular, just an understanding that my machine hangs because I try to use the soundcard like a joystick ;)
So after some tinkering and
printk'ing some values out, I realize that since I wasn't giving a joystick offset, the es1371 driver was skipping right over the joystick code. In reality, (after a bit of looking around) I believe that it only tries to autodetect if there are more than 1 game ports. (Also, the code has a catch for
0x200, since it seems to be a common offset for the gameport). Otherwise, it doesn't even turn the port on.
Luckily, I'm staring right at the code, and I think i understand it ok. So I added an 'else'-clause to the gameport init. code that probes
0x200-0x218(the documented offset range), and then
printk's the probed value.
A prayer to the penguin god, a '
rmmod es1371' and an '
insmod 1371' later and I'm looking at:es1371: found chip, vendor id 0x1274 device id 0x1371 revision 0x07 es1371: debug -> found 0x218. ac97_codec: AC97 Audio codec, id: 0x8384:0x7608 (SigmaTel STAC9708) es1371: found es1371 rev 7 at io 0xe400 irq 5 es1371: features: joystick 0x218
Aha, so my port must have slid over to
0x218, probably due to some small change somewhere else that initialized my hardware differently.
Anyway, so I got it working.
What really makes me sing is that something didn't work, yet because I wanted it to work, and I had the guts to go in and change stuff, it now works.
Now, if I were running Windows and my joystick didn't work, what are the chances that:
- The driver would be open source
- If not, that I would know who the author was
- I would have the author's email address
- He would be awake at 4am
- He would be willing to change things for me
- He would give me a binary to test every 15mins until it worked
I don't think so.
-Gabe has free time after finals, many games to finish
LUGOD: PO Box 1336, Davis, CA 95617 URL: http://www.lugod.org/testimonials/es1371.php
Last updated: 2001 Dec 18 16:07