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

[Maxim Levitsky <maximlevitsky@gmail.com>]

Tomas Winkler wrote:
> On Sun, Jun 15, 2008 at 6:09 PM, Tomas Winkler <tomasw@gmail.com> wro=
te:
>> On Sun, Jun 15, 2008 at 5:12 PM, Maxim Levitsky <maximlevitsky@gmail=
=2Ecom> wrote:
>>> Tomas Winkler wrote:
>>>> On Sun, Jun 15, 2008 at 4:42 PM, Maxim Levitsky <maximlevitsky@gma=
il.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" inste=
ad...
>>>>>>>>>> Give the advantages, I'd like to use it if we can fix the bu=
g (I
>>>>>>>>>> haven't
>>>>>>>>>> seen what the bug is myself). But you are free to change the=
 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 mi=
ne has
>>>>>>>> this card. According to him the card works a lot better with t=
he
>>>>>>>> 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 microcode=
 error.
>>>>>>>
>>>>>> It looks like this is all caused by the big rate, band patch. Lo=
oks
>>>>>> 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 a=
bout 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 f=
irmware?
>>>> 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 i=
t.
>> 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
>=20
>=20
>=20
> Please try this one
>=20
> --- 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,
>=20
>         /* 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;
>=20
>=20


I tested this patch, and it fixes this issue, Thanks a lot.


Best regards,
	Maxim Levitsky

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