From c8106d7625a58ee4387cb2efe3e82320ad44b467 Mon Sep 17 00:00:00 2001 From: Zhu Yi Date: Fri, 8 Jan 2010 10:04:30 -0800 Subject: iwlwifi: fix iwl_queue_used bug when read_ptr == write_ptr When txq read_ptr equals to write_ptr, iwl_queue_used should always return false. Because there is no used TFD in this case. This is a complementary fix to the fix already included in commit "iwl3945: fix panic in iwl3945 driver". Both fixes are needed to address the panic below. This problem was discussed on linux-wireless in http://thread.gmane.org/gmane.linux.kernel.wireless.general/43568 <1>[ 7290.414172] IP: [] iwl3945_rx_reply_tx+0xc1/0x450 [iwl3945] <4>[ 7290.414205] PGD 0 <1>[ 7290.414214] Thread overran stack, or stack corrupted <0>[ 7290.414229] Oops: 0002 [#1] PREEMPT SMP <0>[ 7290.414246] last sysfs file: /sys/devices/platform/coretemp.1/temp1_input <4>[ 7290.414265] CPU 0 <4>[ 7290.414274] Modules linked in: af_packet nfsd usb_storage usb_libusual cpufreq_powersave exportfs cpufreq_conservative iwl3945 nfs cpufreq_userspace snd_hda_codec_realtek acpi_cpufreq uvcvideo lockd iwlcore snd_hda_intel joydev coretemp nfs_acl videodev snd_hda_codec mac80211 v4l1_compat snd_hwdep sbp2 v4l2_compat_ioctl32 uhci_hcd psmouse auth_rpcgss ohci1394 cfg80211 ehci_hcd video ieee1394 snd_pcm serio_raw battery ac nvidia(P) usbcore output sunrpc evdev lirc_ene0100 snd_page_alloc rfkill tg3 libphy fuse lzo lzo_decompress lzo_compress <6>[ 7290.414486] Pid: 0, comm: swapper Tainted: P 2.6.32-rc8-wl #213 Aspire 5720 <6>[ 7290.414507] RIP: 0010:[] [] iwl3945_rx_reply_tx+0xc1/0x450 [iwl3945] <6>[ 7290.414541] RSP: 0018:ffff880002203d60 EFLAGS: 00010246 <6>[ 7290.414557] RAX: 000000000000004f RBX: ffff880064c11600 RCX: 0000000000000013 <6>[ 7290.414576] RDX: ffffffffa0ddcf20 RSI: ffff8800512b7008 RDI: 0000000000000038 <6>[ 7290.414596] RBP: ffff880002203dd0 R08: 0000000000000000 R09: 0000000000000100 <6>[ 7290.414616] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000000000a0 <6>[ 7290.414635] R13: 0000000000000002 R14: 0000000000000013 R15: 0000000000020201 <6>[ 7290.414655] FS: 0000000000000000(0000) GS:ffff880002200000(0000) knlGS:0000000000000000 <6>[ 7290.414677] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b <6>[ 7290.414693] CR2: 0000000000000041 CR3: 0000000001001000 CR4: 00000000000006f0 <6>[ 7290.414712] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <6>[ 7290.414732] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 <4>[ 7290.414752] Process swapper (pid: 0, threadinfo ffffffff81524000, task ffffffff81528b60) <0>[ 7290.414772] Stack: <4>[ 7290.414780] ffff880002203da0 0000000000000046 0000000000000000 0000000000000046 <4>[ 7290.414804] <0> 0000000000000282 0000000000000282 0000000000000282 ffff880064c12010 <4>[ 7290.414830] <0> ffff880002203db0 ffff880064c11600 ffff880064c12e50 ffff8800512b7000 <0>[ 7290.414858] Call Trace: <0>[ 7290.414867] <4>[ 7290.414884] [] iwl3945_irq_tasklet+0x657/0x1740 [iwl3945] <4>[ 7290.414910] [] ? _spin_unlock+0x30/0x60 <4>[ 7290.414931] [] tasklet_action+0x101/0x110 <4>[ 7290.414950] [] __do_softirq+0xc0/0x160 <4>[ 7290.414968] [] call_softirq+0x1c/0x30 <4>[ 7290.414986] [] do_softirq+0x75/0xb0 <4>[ 7290.415003] [] irq_exit+0x95/0xa0 <4>[ 7290.415020] [] do_IRQ+0x77/0xf0 <4>[ 7290.415038] [] ret_from_intr+0x0/0xf <0>[ 7290.415052] <4>[ 7290.415067] [] ? acpi_idle_enter_bm+0x270/0x2a5 <4>[ 7290.415087] [] ? acpi_idle_enter_bm+0x27a/0x2a5 <4>[ 7290.415107] [] ? acpi_idle_enter_bm+0x270/0x2a5 <4>[ 7290.415130] [] ? cpuidle_idle_call+0x93/0xf0 <4>[ 7290.415149] [] ? cpu_idle+0xa7/0x110 <4>[ 7290.415168] [] ? rest_init+0x75/0x80 <4>[ 7290.415187] [] ? start_kernel+0x3a7/0x3b3 <4>[ 7290.415206] [] ? x86_64_start_reservations+0x125/0x129 <4>[ 7290.415227] [] ? x86_64_start_kernel+0xe4/0xeb <0>[ 7290.415243] Code: 00 41 39 ce 0f 8d e8 01 00 00 48 8b 47 40 48 63 d2 48 69 d2 98 00 00 00 4c 8b 04 02 48 c7 c2 20 cf dd a0 49 8d 78 38 49 8d 40 4f 47 09 00 c6 47 0c 00 c6 47 0f 00 c6 47 12 00 c6 47 15 00 49 <1>[ 7290.415382] RIP [] iwl3945_rx_reply_tx+0xc1/0x450 [iwl3945] <4>[ 7290.415410] RSP <0>[ 7290.415421] CR2: 0000000000000041 <4>[ 7290.415436] ---[ end trace ec46807277caa515 ]--- <0>[ 7290.415450] Kernel panic - not syncing: Fatal exception in interrupt <4>[ 7290.415468] Pid: 0, comm: swapper Tainted: P D 2.6.32-rc8-wl #213 <4>[ 7290.415486] Call Trace: <4>[ 7290.415495] [] panic+0x7d/0x13a <4>[ 7290.415519] [] oops_end+0xda/0xe0 <4>[ 7290.415538] [] no_context+0xea/0x250 <4>[ 7290.415557] [] ? select_task_rq_fair+0x511/0x780 <4>[ 7290.415578] [] __bad_area_nosemaphore+0x125/0x1e0 <4>[ 7290.415597] [] ? __enqueue_entity+0x7c/0x80 <4>[ 7290.415616] [] ? enqueue_task_fair+0x111/0x150 <4>[ 7290.415636] [] bad_area_nosemaphore+0xe/0x10 <4>[ 7290.415656] [] do_page_fault+0x26a/0x320 <4>[ 7290.415674] [] page_fault+0x1f/0x30 <4>[ 7290.415697] [] ? iwl3945_rx_reply_tx+0xc1/0x450 [iwl3945] <4>[ 7290.415723] [] iwl3945_irq_tasklet+0x657/0x1740 [iwl3945] <4>[ 7290.415746] [] ? _spin_unlock+0x30/0x60 <4>[ 7290.415764] [] tasklet_action+0x101/0x110 <4>[ 7290.415783] [] __do_softirq+0xc0/0x160 <4>[ 7290.415801] [] call_softirq+0x1c/0x30 <4>[ 7290.415818] [] do_softirq+0x75/0xb0 <4>[ 7290.415835] [] irq_exit+0x95/0xa0 <4>[ 7290.415852] [] do_IRQ+0x77/0xf0 <4>[ 7290.415869] [] ret_from_intr+0x0/0xf <4>[ 7290.415883] [] ? acpi_idle_enter_bm+0x270/0x2a5 <4>[ 7290.415911] [] ? acpi_idle_enter_bm+0x27a/0x2a5 <4>[ 7290.415931] [] ? acpi_idle_enter_bm+0x270/0x2a5 <4>[ 7290.415952] [] ? cpuidle_idle_call+0x93/0xf0 <4>[ 7290.415971] [] ? cpu_idle+0xa7/0x110 <4>[ 7290.415989] [] ? rest_init+0x75/0x80 <4>[ 7290.416007] [] ? start_kernel+0x3a7/0x3b3 <4>[ 7290.416026] [] ? x86_64_start_reservations+0x125/0x129 <4>[ 7290.416047] [] ? x86_64_start_kernel+0xe4/0xeb Reported-by: Maxim Levitsky Tested-by: Maxim Levitsky Signed-off-by: Zhu Yi Signed-off-by: Reinette Chatre CC: stable@kernel.org Signed-off-by: John W. Linville --- drivers/net/wireless/iwlwifi/iwl-dev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/wireless/iwlwifi/iwl-dev.h') diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h index 165d1f6e2dd9..3822cf53e368 100644 --- a/drivers/net/wireless/iwlwifi/iwl-dev.h +++ b/drivers/net/wireless/iwlwifi/iwl-dev.h @@ -711,7 +711,7 @@ extern void iwl_txq_ctx_stop(struct iwl_priv *priv); extern int iwl_queue_space(const struct iwl_queue *q); static inline int iwl_queue_used(const struct iwl_queue *q, int i) { - return q->write_ptr > q->read_ptr ? + return q->write_ptr >= q->read_ptr ? (i >= q->read_ptr && i < q->write_ptr) : !(i < q->read_ptr && i >= q->write_ptr); } -- cgit v1.2.2