On Fri, 20 Nov 2009 14:05:25 -0600 Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote: > On 11/20/2009 01:58 PM, Chris Vine wrote: > > On Fri, 20 Nov 2009 06:43:05 -0600 > > Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote: > >> One last check. I would appreciate receiving answers to the > >> following questions. These questions apply to anyone else with > >> this problem. > >> > >> Does the pm_qos patch help your "fatal DMA error" problem, > >> particularly when booted from power-off? > >> > >> If you warm-boot after loading the wl driver, does the patch make > >> any difference? > > > > What's the date/time of the last patch you posted for this and what > > kernel does it apply to? > > Friday 11/13 ar 22:38 CET. The link is at > https://lists.berlios.de/pipermail/bcm43xx-dev/2009-November/006338.html. > > The patch is written for wireless-testing, but it should apply on > mainline kernels as well. OK. I have applied the patch to mainline kernel 2.6.32-rc8. COLD BOOT On a cold boot, the patch gives rise to a very substantial improvement. Without it, with the processor acpi module loaded, often just bringing up the interface would cause the DMA errors, and if that didn't do it then running 'iwlist scan' a few times always would. At that point the wireless device required a cold boot to get it working again. With the patch applied and with the processor acpi module loaded it works well for a period - I can bring up the interface, associate with my wireless router and do some web browsing. However if I gave it a stress test by rsyncing a large directory (actually all my mozilla/firefox caches) then after a while, say 1 minute of full speed throughput, I got the kernel warning at the end of this post. Shortly after this the DMA errors arose, all throughput ceased and shortly afterwards I got a complete kernel lock-up. (I couldn't ssh in or nor did anything appear in the logs.) I was not able to capture the text of the DMA errors but they followed the usual pattern. This is pretty well the same effect as not applying the patch and blacklisting the processor module: I reported a few weeks ago that blacklisting that module solves the DMA problem for me, but further testing showed that to be wrong - I got kernel warnings (sorry I didn't save them) followed by the usual DMA errors following sometimes by a kernel lock-up. WARM BOOT FROM KERNEL WITH WL MODULE INSTALLED The patched kernel makes no change on a warm boot in the sense that if I warm boot after initialising the wireless device with the wl module then the b43 module appears to work correctly, both with and without the patch applied. On the same stress test as mentioned above, I have not been able to induce the DMA errors nor kernel warnings. It resolutely refuses to do anything except work correctly. KERNEL WARNING The kernel warning I induced on a cold boot was as follows: WARNING: at drivers/net/wireless/b43/dma.c:1151 b43_dma_handle_txstatus+0x55/0x420 [b43]() Hardware name: 20021,2959 Modules linked in: arc4 ecb b43 ssb mmc_core pcmcia mac80211 cfg80211 led_class pcmcia_core i915 drm_kms_helper drm i2c_algo_bit snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss sco bnep rfcomm l2cap crc16 nfsd exportfs nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables xt_helper xt_conntrack xt_state x_tables nf_conntrack_irc nf_conntrack_ftp nf_conntrack parport_pc parport fuse snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm uvcvideo rtc_cmos btusb bluetooth rtc_core intel_agp rfkill snd_timer battery ac videodev rtc_lib video processor thermal usbhid tg3 psmouse v4l1_compat snd wmi thermal_sys agpgart button output hwmon i2c_i801 evdev libphy soundcore sg serio_raw snd_page_alloc Pid: 4412, comm: irq/17-b43 Not tainted 2.6.32-rc8 #1 Call Trace: [<f8dd4c95>] ? b43_dma_handle_txstatus+0x55/0x420 [b43] [<c10328fc>] warn_slowpath_common+0x7c/0xa0 [<f8dd4c95>] ? b43_dma_handle_txstatus+0x55/0x420 [b43] [<c1032935>] warn_slowpath_null+0x15/0x20 [<f8dd4c95>] b43_dma_handle_txstatus+0x55/0x420 [b43] [<c10265e1>] ? __dequeue_entity+0x21/0x40 [<c1028ee9>] ? finish_task_switch+0x39/0x80 [<f8dceb7e>] b43_handle_txstatus+0x6e/0x80 [b43] [<f8dbcdbb>] b43_do_interrupt_thread+0x21b/0x910 [b43] [<c102a34f>] ? try_to_wake_up+0x8f/0x210 [<f8dbd518>] b43_interrupt_thread_handler+0x18/0x30 [b43] [<c1068580>] irq_thread+0xc0/0x1a0 [<c10684c0>] ? irq_thread+0x0/0x1a0 [<c104ac24>] kthread+0x74/0x80 [<c104abb0>] ? kthread+0x0/0x80 [<c100384f>] kernel_thread_helper+0x7/0x38 ---[ end trace 778fc6df7aca6d14 ]--- ------------[ cut here ]------------ WARNING: at drivers/net/wireless/b43/dma.c:1154 b43_dma_handle_txstatus+0x6e/0x420 [b43]() Hardware name: 20021,2959 Modules linked in: arc4 ecb b43 ssb mmc_core pcmcia mac80211 cfg80211 led_class pcmcia_core i915 drm_kms_helper drm i2c_algo_bit snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss sco bnep rfcomm l2cap crc16 nfsd exportfs nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables xt_helper xt_conntrack xt_state x_tables nf_conntrack_irc nf_conntrack_ftp nf_conntrack parport_pc parport fuse snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm uvcvideo rtc_cmos btusb bluetooth rtc_core intel_agp rfkill snd_timer battery ac videodev rtc_lib video processor thermal usbhid tg3 psmouse v4l1_compat snd wmi thermal_sys agpgart button output hwmon i2c_i801 evdev libphy soundcore sg serio_raw snd_page_alloc Pid: 4412, comm: irq/17-b43 Tainted: G W 2.6.32-rc8 #1 Call Trace: [<f8dd4cae>] ? b43_dma_handle_txstatus+0x6e/0x420 [b43] [<c10328fc>] warn_slowpath_common+0x7c/0xa0 [<f8dd4cae>] ? b43_dma_handle_txstatus+0x6e/0x420 [b43] [<c1032935>] warn_slowpath_null+0x15/0x20 [<f8dd4cae>] b43_dma_handle_txstatus+0x6e/0x420 [b43] [<c10265e1>] ? __dequeue_entity+0x21/0x40 [<c1028ee9>] ? finish_task_switch+0x39/0x80 [<f8dceb7e>] b43_handle_txstatus+0x6e/0x80 [b43] [<f8dbcdbb>] b43_do_interrupt_thread+0x21b/0x910 [b43] [<c102a34f>] ? try_to_wake_up+0x8f/0x210 [<f8dbd518>] b43_interrupt_thread_handler+0x18/0x30 [b43] [<c1068580>] irq_thread+0xc0/0x1a0 [<c10684c0>] ? irq_thread+0x0/0x1a0 [<c104ac24>] kthread+0x74/0x80 [<c104abb0>] ? kthread+0x0/0x80 [<c100384f>] kernel_thread_helper+0x7/0x38 ---[ end trace 778fc6df7aca6d15 ]--- Chris -- 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
