Re: [ipw3945-devel] [BUG] iwlwifi 3945 works only with disable_hw_scan=1

["Tomas Winkler" <tomasw@gmail.com>]

On Mon, Jun 16, 2008 at 8:50 AM, Maxim Levitsky <maximlevitsky@gmail.co=
m> wrote:
> Tomas Winkler wrote:
>>
>> On Sun, Jun 15, 2008 at 6:09 PM, Tomas Winkler <tomasw@gmail.com> wr=
ote:
>>>
>>> On Sun, Jun 15, 2008 at 5:12 PM, Maxim Levitsky <maximlevitsky@gmai=
l.com>
>>> wrote:
>>>>
>>>> Tomas Winkler wrote:
>>>>>
>>>>> On Sun, Jun 15, 2008 at 4:42 PM, Maxim Levitsky
>>>>> <maximlevitsky@gmail.com>
>>>>> wrote:
>>>>>>
>>>>>> Tomas Winkler wrote:
>>>>>>>
>>>>>>> On Fri, Jun 13, 2008 at 6:06 PM, Maxim Levitsky
>>>>>>> <maximlevitsky@gmail.com>
>>>>>>> wrote:
>>>>>>>>
>>>>>>>> Tor H=E5kon Haugen wrote:
>>>>>>>>>
>>>>>>>>> John W. Linville wrote:
>>>>>>>>>>
>>>>>>>>>> On Fri, Jun 13, 2008 at 03:35:23PM +0800, Zhu Yi wrote:
>>>>>>>>>>>
>>>>>>>>>>> On Thu, 2008-06-12 at 09:59 -0400, John W. Linville wrote:
>>>>>>>>>>>>
>>>>>>>>>>>> Honestly I'm tempted to change it to "enable_hw_scan" inst=
ead...
>>>>>>>>>>>
>>>>>>>>>>> Give the advantages, I'd like to use it if we can fix the b=
ug (I
>>>>>>>>>>> haven't
>>>>>>>>>>> seen what the bug is myself). But you are free to change th=
e
>>>>>>>>>>> default
>>>>>>>>>>> value until it is fixed. There is no such problem for 4965,
>>>>>>>>>>> right?
>>>>>>>>>>
>>>>>>>>>> AFAICT only the 3945 seems to need it.
>>>>>>>>>>
>>>>>>>>> I can confirm that this also applies to 4965 as a friend of m=
ine
>>>>>>>>> has
>>>>>>>>> this card. According to him the card works a lot better with =
the
>>>>>>>>> parameters "swcrypto=3D1" and "disable_hw_scan=3D1".
>>>>>>>>
>>>>>>>> Just to make it clear,
>>>>>>>> iwl3945 doesn't work at all without disable_hw_scan=3D1 here.
>>>>>>>> The driver just shuts down thee card since it detects microcod=
e
>>>>>>>> error.
>>>>>>>>
>>>>>>> It looks like this is all caused by the big rate, band patch. L=
ooks
>>>>>>> like A band scan channels are not configured correctly for the
>>>>>>> scanning. This crashes the firmware.
>>>>>>>
>>>>>>> Tomas
>>>>>>
>>>>>> Probably, I see that eeprom according to dmesg contains no info =
about
>>>>>> A
>>>>>> channels, so maybe this crashes the firmware.
>>>>>>
>>>>> Can you please send your dmesg.
>>>>
>>>> I did that
>>>> (You mean dmesg without disable_hw_scan=3D1?)
>>>>
>>>> If not what debug options I should include
>>>> (I tried same firmware debug options, but the log wrapped around.)
>>>>
>>>> dmesg without disable_hw_scan=3D1 attached.
>>>>
>>>>
>>>>>> I have few questions:
>>>>>>
>>>>>> * Is there a software workaround without the need to update the
>>>>>> firmware?
>>>>>
>>>>> Yes
>>>>>
>>>>>> * Is the firmware error so harmful, so driver can't continue?
>>>>>
>>>>> This is firmware misconfiguration.  Driver should be friendly to
>>>>> firmware and use correctly API.
>>>>>
>>>>>> * Can I expect updated version of the firmware with  fix?
>>>>>
>>>>> No need so far.
>>>>>
>>>>>> Sadly this confirms that firmware is worse that I thought, it is
>>>>>> closer
>>>>>> to
>>>>>> closed drivers.
>>>>>
>>>>> The firmware API is open, it just wasn't used correctly.
>>>>
>>>> I mean if there is a bug in firmware, nobody expect intel can fix =
it.
>>>
>>> Intel is fixing bugs in the firmware. Still this doesn't look like =
a
>>> firmware error.
>>>
>>>> BTW you say that firmware api is open,
>>>> is there a programming manual for this wireless chip?
>>>
>>> it's well documented in -commands.h file
>>
>>
>>
>> Please try this one
>>
>> --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
>> +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
>> @@ -3348,7 +3348,10 @@ static void
>> iwl3945_rx_scan_complete_notif(struct iwl3945_priv *priv,
>>
>>        /* Remove this scanned band from the list
>>         * of pending bands to scan */
>> -       priv->scan_bands--;
>> +       if (priv->cfg->sku & IWL_SKU_A)
>> +               priv->scan_bands--;
>> +       else
>> +               priv->scan_bands =3D 0;
>>
>>
>
>
> I tested this patch, and it fixes this issue, Thanks a lot.
>
Thanks a lot for helping resolve this. I will post an official patch.
Tomas
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