Messages in this thread | | | Date | Mon, 22 Nov 1999 15:35:54 -0500 (EST) | From | Christopher Neufeld <> | Subject | Fix for sound problems on ad1848 after laptop suspend |
| |
I originally tried to send this message to Hannu Savolainen, but the email address in the 2.2.13 CREDITS file seems no longer to be correct. Editing slightly for a broadcast audience:
Some people may be aware of problems with laptops and the cs423* chips run on the ad1848.c driver. I have such a setup in my Dell Inspiron 3500 laptop computer. The sound driver fails to work after the first time the system is put into suspend mode by closing the laptop's cover. The sound becomes broken, stuttering or ending early. "dmesg" reports DMA/DRQ configuration problems. The computer has to be power cycled in order to get the sound working again, though some commercial drivers can handle the suspend.
Chris Studholme (Chris.Studholme@ualberta.ca) has a web page at:
http://www.bus.ualberta.ca/cstudhol/unix/inspiron.html
in which he describes a hack which fixes the problem for him. I've tested it, and found that it works for my laptop. A cursory examination of the kernel logs suggests that it works by forcing the sound hardware into 8-bit soundblaster compatibility mode, then switching back into native mode. This seems to get the hardware back in a useful state. It occurs to me that someone might want to see if there's some way to embed a similar functionality in the ad1848.c driver code, so that if the sound fails, the hardware can be toggled into soundblaster mode and back again. Right now, I've got a small script which is run by apmd whenever the system resumes from a suspend, but I gather that this problem is very common on laptops, and not just on Dell, judging by the number of people with problems on dejanews. Having the driver fix itself would be nice for those people.
-- Christopher Neufeld neufeld@physics.utoronto.ca Home page: http://caliban.physics.utoronto.ca/neufeld/Intro.html "Don't edit reality for the sake of simplicity"
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |