On 08.12.2013 08:19, Emmanuel Grumbach wrote:
On Sun, Dec 8, 2013 at 8:21 AM, Jeremy Johnathan Rodent
<rat.o.drat@xxxxxxxxx> wrote:
Hello.
I'd like to apologize in advance, if I shouldn't report such issues to this
mailing list. I was told this is a good place for bug reports associated
with Linux kernel modules for wireless devices.
I have a ThinkPad X201 Tablet, which I recently bought used. This laptop has
an Intel Centrino Ultimate-N 6300 wireless 802.11abgn card, which is
supported via the iwlwifi module and a firmware image. I'm using Arch Linux
on it (i haven't tried a different OS yet), and so have fairly recent and
vanilla kernel and firmware packages (the policy of this distribution is to
have the latest packages marked as stable by upstream and only do patching
if it's required to build the package or make it work with others).
Since some time I've been struggling with my laptop's wifi card randomly
locking up (at least, I think the hardware locks up), usually after at least
a few hours of usage. The initial symptom of such an event is the wifi card
ceasing to work. Afterwards, each few seconds the computer "freezes" for a
few other seconds. I can stop these freezes by flipping a radio disable
switch, which causes rfkill's hard block on all wireless devices. However,
flipping it back to unblock doesn't cause the wifi card to function, only
bringing back aforementioned freezes.
These lock-ups happen completely randomly. I'm using this laptop a lot, over
10 hours daily, and there are days when there is no problem. I even managed
to use it a week without problems. Other times it can happen as much as 4
times daily. Twice it happened straight after boot, but otherwise it happens
after at least a few hours of usage.
I at first thought, that it might be associated with the amount of data sent
in and out of the interface, but there was no correlation. I specially
tested this by moving large amounts of data within my local network for a
few hours. Next thing I considered, was that the device overheats due to
radiation (I'm usually very close to my AP, and have the default tx-power
setting, which is 15dBm). But these issues happened no matter how far I was
and changing tx-power to smallest possible value didn't help. I also thought
this might be because the device accumulates heat after a few hours, but
recently I got the lock-up 3 minutes after boot, which happened after the
laptop was laying all night powered off.
Since this issues started, I've considered many packages (such as those
network-related and kernel modules like tp-smapi) as the culprits
(especially those installed or updated around the time of the first
occurrence) and tried uninstalling or downgrading. I also tried removing any
module options and udev rules I made before the lock-ups started. Again, no
success.
Finally, I recently tried a few options of the iwlwifi module
(11n_disable=1, swcrypto=1, bt_coex_active=0). None of those helped, though
after setting bt_coex_active=0 I had 2 days of peace. I haven't tried the
power-saving ones yet, though.
My only remaining clue is that this seems more likely to happen if I'm on
battery power, especially when the battery has little charge. So I guess
this might be associated with power management.
I have to say, I don't have the knowledge to understand what's really going
on, how to read the ring buffer output or how to debug such an issue. But it
seems to me, looking at the dmesg output, that the driver has some issue,
the device is reinitialized, which fails. Hence why I wrote that the device
locks up.
I've attached output of dmesg captured right after a recent lock-up. I hope
I have a recent enough kernel for this to be useful. I also attached outputs
of dmidecode and lspci -vvvv, and /proc/config.gz, in case this information
would be useful.
Please tell me if anything else is needed. I'm willing to invest some time
and have no problem with things like compiling a custom kernel, using gdb.
The only problem here is that I have no idea how I can trigger this, and can
never be sure if the issue went away.
I thank in advance for any help.
can you please apply this and report back?
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c
b/drivers/net/wireless/iwlwifi/pcie/tx.c
index c5746ed..0a1f39c 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -708,10 +708,6 @@ void iwl_pcie_tx_start(struct iwl_trans *trans,
u32 scd_base_addr)
reg_val = iwl_read_direct32(trans, FH_TX_CHICKEN_BITS_REG);
iwl_write_direct32(trans, FH_TX_CHICKEN_BITS_REG,
reg_val | FH_TX_CHICKEN_BITS_SCD_AUTO_RETRY_EN);
-
- /* Enable L1-Active */
- iwl_clear_bits_prph(trans, APMG_PCIDEV_STT_REG,
- APMG_PCIDEV_STT_VAL_L1_ACT_DIS);
}
void iwl_trans_pcie_tx_reset(struct iwl_trans *trans)
Sorry it took so long.
I've built 3.12.3 with this patch applied. What now?
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