On Fri, 26 Feb 2010, Larry Finger wrote: > > If you do the following (as root): > > modprobe -r b43 > echo 6400 > /sys/kernel/debug/tracing/buffer_size_kb > echo mmiotrace > /sys/kernel/debug/tracing/current_tracer > cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & > modprobe b43 > > do some network activity, then > > echo nop > /sys/kernel/debug/tracing/current_tracer > sleep 1 > killproc cat > > That should be a good enough test. If your machine behaves the same as has been > reported, you should see a DMA error at the point that tracing is turned off. Nope. I get the DMA error immediately, even if I'm tracing. Here: - turn on tracing: Feb 26 13:35:45 localhost kernel: mmiotrace: Disabling non-boot CPUs... Feb 26 13:35:45 localhost kernel: Broke affinity for irq 9 Feb 26 13:35:45 localhost kernel: Broke affinity for irq 12 Feb 26 13:35:45 localhost kernel: Broke affinity for irq 26 Feb 26 13:35:45 localhost kernel: CPU 1 is now offline Feb 26 13:35:45 localhost kernel: SMP alternatives: switching to UP code Feb 26 13:35:45 localhost kernel: mmiotrace: CPU1 is down. Feb 26 13:35:45 localhost kernel: mmiotrace: enabled. - insmod b43: Feb 26 13:36:31 localhost kernel: cfg80211: Calling CRDA to update world regulatory domain ... Feb 26 13:36:31 localhost kernel: b43 ssb0:0: firmware: requesting b43/lp0initvals15.fw Feb 26 13:36:31 localhost kernel: b43 ssb0:0: firmware: requesting b43/lp0bsinitvals15.fw Feb 26 13:36:32 localhost kernel: b43-phy0: Loading firmware version 478.104 (2008-07-01 00:50:23) Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: Fatal DMA error: 0x00000400, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: This device does not support DMA on your system. Please use PIO instead. Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: CONFIG_B43_FORCE_PIO must be set in your kernel configuration. Feb 26 13:36:34 localhost kernel: b43-phy0: Controller RESET (DMA error) ... Feb 26 13:36:34 localhost kernel: b43-phy0: Loading firmware version 478.104 (2008-07-01 00:50:23) .. - networking works (because this kernel had the PIO fallback patch) - turn off tracing: Feb 26 13:37:15 localhost kernel: mmiotrace: purging non-iounmapped trace @0xffffc90022560000, size 0x4000. Feb 26 13:37:15 localhost kernel: mmiotrace: Re-enabling CPUs... Feb 26 13:37:15 localhost kernel: SMP alternatives: switching to SMP code Feb 26 13:37:15 localhost kernel: Booting Node 0 Processor 1 APIC 0x1 Feb 26 13:37:15 localhost kernel: mmiotrace: enabled CPU1. Feb 26 13:37:15 localhost kernel: mmiotrace: disabled. so even if mmiotrace fixes it for others, it's not working for me. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
