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)
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