Hi Stanislaw, On Fri, 2011-02-25 at 07:57 -0800, Stanislaw Gruszka wrote: > Since commit commit 470058e0ad82fcfaaffd57307d8bf8c094e8e9d7 > "iwlwifi: avoid Tx queue memory allocation in interface down" we do > not unmap dma and free skbs when down device and there is pending > transfer. What in consequence may cause that system hung (waiting > for free skb's) when performing shutdown at iptables module unload. > > DMA leak manifest itself following warning: > > WARNING: at lib/dma-debug.c:689 dma_debug_device_change+0x15a/0x1b0() > Hardware name: HP xw8600 Workstation > pci 0000:80:00.0: DMA-API: device driver has pending DMA allocations while released from device [count=240] > Modules linked in: iwlagn(-) aes_x86_64 aes_generic fuse cpufreq_ondemand acpi_cpufreq freq_table mperf xt_physdev ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 ext3 jbd dm_mirror dm_region_hash dm_log dm_mod uinput hp_wmi sparse_keymap sg wmi microcode serio_raw tg3 arc4 ecb shpchp mac80211 cfg80211 rfkill ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif firewire_ohci firewire_core crc_itu_t mptsas mptscsih mptbase scsi_transport_sas pata_acpi ata_generic ata_piix ahci libahci floppy nouveau ttm drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: iwlagn] > Pid: 9131, comm: rmmod Tainted: G W 2.6.38-rc6-wl+ #33 > Call Trace: > [<ffffffff810649ef>] ? warn_slowpath_common+0x7f/0xc0 > [<ffffffff81064ae6>] ? warn_slowpath_fmt+0x46/0x50 > [<ffffffff812320ab>] ? dma_debug_device_change+0xdb/0x1b0 > [<ffffffff8123212a>] ? dma_debug_device_change+0x15a/0x1b0 > [<ffffffff8149dc18>] ? notifier_call_chain+0x58/0xb0 > [<ffffffff8108e370>] ? __blocking_notifier_call_chain+0x60/0x90 > [<ffffffff8108e3b6>] ? blocking_notifier_call_chain+0x16/0x20 > [<ffffffff812f570c>] ? __device_release_driver+0xbc/0xe0 > [<ffffffff812f5808>] ? driver_detach+0xd8/0xe0 > [<ffffffff812f45d1>] ? bus_remove_driver+0x91/0x100 > [<ffffffff812f6022>] ? driver_unregister+0x62/0xa0 > [<ffffffff8123d5d4>] ? pci_unregister_driver+0x44/0xa0 > [<ffffffffa05632d1>] ? iwl_exit+0x15/0x1c [iwlagn] > [<ffffffff810ab492>] ? sys_delete_module+0x1a2/0x270 > [<ffffffff81498da9>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff8100bf42>] ? system_call_fastpath+0x16/0x1b > > I still can observe above warning after apply patch, but it is very > hard to reproduce it, and have count=1. Whereas that one is easy to > reproduce using debugfs force_reset while transmitting data, and have > very big counts eg. 240, like quoted here. So count=1 WARNING seems > to be different issue that need to be resolved separately. > > v1 -> v2: fix infinity loop bug I made during "for" to "while" loop transition. > > Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> > --- > drivers/net/wireless/iwlwifi/iwl-agn-tx.c | 12 ++++- > drivers/net/wireless/iwlwifi/iwl-core.h | 2 + > drivers/net/wireless/iwlwifi/iwl-tx.c | 73 +++++++++++++++++++---------- > 3 files changed, 61 insertions(+), 26 deletions(-) > Good catch, thank you very much I don't think we need EXPORT_SYMBOL anymore after driver split Wey -- 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
