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These are general Dell laptop problems, and so far as I can tell, there's no solution yet to either. Audio is quite hard (except to get apps to use bigger buffers; try googling for 'hammerfall cardbus dell', it's a common problem). This page: http://www-106.ibm.com/developerworks/library/l-hw2.html may contain a solution to the audio issue, too, I just discovered. The clock problem is something Linux should deal with. Like to look into it? I can help somewhat. Andrew --On Tuesday, January 14, 2003 01:14:31 -0500 Valdis.Kletnieks@vt.edu wrote: > A while back, I reported nasty sound distortion/echoing problems > on a C840. Well, this is a follow-up that I found the cause of the > problem... > > I was also running gkrellm, with it's APM monitor activated. Whenever > it read from /proc/apm, this would cause a call to the BIOS down in > apm_get_power_status(). As near as I can tell, on this particular Dell, > calling the APM drops interrupts on the floor even if you run with > CONFIG_APM_ALLOW_INTS. Another effect of this was a badly drifting > clock (which is how I found this in the first place) - doing a > a 'grep timer /proc/interrupts', waiting 4 or 5 minutes of wall clock > time, doing it again, and doing the math showed only 980 or so interrupts > per second. The clock drift exhibits itself under 2.4.18 as well, > but it wasn't breaking audio. > > My guess is that the 2.4 driver for the i810 audio is a bit more tolerant > of the occasional dropped interrupt (it seems to like to keep a lot of > data already queued in the ring buffer), but the 2.5 driver runs in much > more 'just in time' mode. As a result, if the kernel gets suspended while > we monkey around in the BIOS, we get a data underrun, causing my problems. > > For what it's worth, the i8k plugin for gkrellm also causes clock drift, > but doesn't seem to upset the audio driver. > > (OK, so it's not as glorious as debugging APIC issues on a NUMAQ system. > On the other hand, there's probably a lot more Latitudes out there than > NUMAQ boxes, and more importantly to *me*, I have to deal with this > particular Latitude 8-10 hours a day. And somebody made a comment about > open source being driven to scratch itches... ;) > > /Valdis > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | |||||||||
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