[RFC PATCH] bcm43xx: set channel when the interface is brought up

[RFC PATCH] bcm43xx: set channel when the interface is brought up

[Pavel Roskin]

Hello!

I have discovered that while I can indeed associate without
wpa_supplicant using bcm43xx_d80211 driver, I have to set the channel
every time the interface is brought down and up.

It turns out d80211 uses the "config" method of the hardware drivers
very sparingly.  It's only used for scanning and in ioctl commands.  It
is not called after the interface has been brought up with the "open"
method.

I don't know whose responsibility it should be to apply the
configuration when the interface is brought up.  I'm not familiar with
d80211 design principles.

If the hardware drivers are supposed to do it, here's my patch.  It is
working fine for me and ready to be applied.  The changelog is in the
subject.

Signed-off-by: Pavel Roskin <proski-mXXj517/zsQ@public.gmane.org>
---

 drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c b/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
index 9f4d51d..d408e38 100644
--- a/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
+++ b/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
@@ -2809,6 +2809,9 @@ static int bcm43xx_dev_open(struct ieee80211_hw *hw)
 	}
 	mutex_unlock(&wl->mutex);
 
+	if (!err)
+		err = bcm43xx_dev_config(hw, &hw->conf);
+
 	return err;
 }
 


-- 
Regards,
Pavel Roskin

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Jiri Benc]

On Thu, 25 Jan 2007 01:50:54 -0500, Pavel Roskin wrote:
> It turns out d80211 uses the "config" method of the hardware drivers
> very sparingly.  It's only used for scanning and in ioctl commands.  It
> is not called after the interface has been brought up with the "open"
> method.
> 
> I don't know whose responsibility it should be to apply the
> configuration when the interface is brought up.  I'm not familiar with
> d80211 design principles.

I think it should be done in the stack (actually, it's on todo list for
quite some time). However, I don't consider this as a big problem -
just do it in a driver (like your patch does) for now.

 Jiri

-- 
Jiri Benc
SUSE Labs

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Ivo Van Doorn]

Hi,

> I have discovered that while I can indeed associate without
> wpa_supplicant using bcm43xx_d80211 driver, I have to set the channel
> every time the interface is brought down and up.
>
> It turns out d80211 uses the "config" method of the hardware drivers
> very sparingly.  It's only used for scanning and in ioctl commands.  It
> is not called after the interface has been brought up with the "open"
> method.

Correct, similar problems have been detected in rt2x00. The temporary
solution in there is to demand a scanning operation after the interface
has been brought up.

> I don't know whose responsibility it should be to apply the
> configuration when the interface is brought up.  I'm not familiar with
> d80211 design principles.

Well my personal preference would be if the dscape stack handles it,
unless the stack guarentees the conf structure has been initialized
and contains valid data when the interface is being brought up.

Ivo

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Jiri Benc]

On Thu, 25 Jan 2007 12:47:08 +0100, Ivo Van Doorn wrote:
> Correct, similar problems have been detected in rt2x00. The temporary
> solution in there is to demand a scanning operation after the interface
> has been brought up.

Scanning? No no no, please! That would be a clear bug and misbehaviour.

 Jiri

-- 
Jiri Benc
SUSE Labs

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Ivo Van Doorn]

Hi,

> > Correct, similar problems have been detected in rt2x00. The temporary
> > solution in there is to demand a scanning operation after the interface
> > has been brought up.
>
> Scanning? No no no, please! That would be a clear bug and misbehaviour.

Hmm, I think I forgot to add one little thing in my comment.
The scanning operation is demanded in the rt2x00 README, so the driver
doesn't start the scanning automatically and just awaits the user commands.
The user is also free to change the channel to make the configuration active.
But a scanning command will also display if it has at least found some AP,
so without scanning results attempting to scan will very likely fail. ;)

Ivo

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Gene Heskett]

On Thursday 25 January 2007 07:50, Jiri Benc wrote:
>On Thu, 25 Jan 2007 12:47:08 +0100, Ivo Van Doorn wrote:
>> Correct, similar problems have been detected in rt2x00. The temporary
>> solution in there is to demand a scanning operation after the
>> interface has been brought up.
>
>Scanning? No no no, please! That would be a clear bug and misbehaviour.
>
> Jiri

Oh?  I'm sitting here watching the tty0 screen of my lappy after x has 
been started, and I have established a connection, but SoftMAC is still 
logging its scan activity, starting with channel 1 and scanning 14 
channels.  Its doing this at approximately 2 minute intervals.  So I 
think we have your definition of a clear bug and misbehaviour.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2007 by Maurice Eugene Heskett, all rights reserved.

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Jiri Benc]

On Thu, 25 Jan 2007 09:05:32 -0500, Gene Heskett wrote:
> Oh?  I'm sitting here watching the tty0 screen of my lappy after x has 
> been started, and I have established a connection, but SoftMAC is still 
> logging its scan activity, starting with channel 1 and scanning 14 
> channels.  Its doing this at approximately 2 minute intervals.  So I 
> think we have your definition of a clear bug and misbehaviour.

Yes. As well as some other wireless drivers. But that's not worth
fixing.

Also, please note that softmac isn't going to do user space MLME so
it is not relevant at all.

 Jiri

-- 
Jiri Benc
SUSE Labs

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Gene Heskett]

On Thursday 25 January 2007 09:23, Jiri Benc wrote:
>On Thu, 25 Jan 2007 09:05:32 -0500, Gene Heskett wrote:
>> Oh?  I'm sitting here watching the tty0 screen of my lappy after x has
>> been started, and I have established a connection, but SoftMAC is
>> still logging its scan activity, starting with channel 1 and scanning
>> 14 channels.  Its doing this at approximately 2 minute intervals.  So
>> I think we have your definition of a clear bug and misbehaviour.
>
>Yes. As well as some other wireless drivers. But that's not worth
>fixing.
>
>Also, please note that softmac isn't going to do user space MLME so
>it is not relevant at all.

MLME?  More acronyms I've not put in my wet dictionary.. :)

> Jiri

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2007 by Maurice Eugene Heskett, all rights reserved.

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Johannes Berg]

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On Thu, 2007-01-25 at 09:34 -0500, Gene Heskett wrote:

> MLME?  More acronyms I've not put in my wet dictionary.. :)

The 802.11 specs have a huge list of acronyms you might want to be
somewhat familiar with. I think I have a printout somewhere, can't ever
remember them either ;)

johannes

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Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Larry Finger]

Gene Heskett wrote:
> On Thursday 25 January 2007 07:50, Jiri Benc wrote:
>> On Thu, 25 Jan 2007 12:47:08 +0100, Ivo Van Doorn wrote:
>>> Correct, similar problems have been detected in rt2x00. The temporary
>>> solution in there is to demand a scanning operation after the
>>> interface has been brought up.
>> Scanning? No no no, please! That would be a clear bug and misbehaviour.
>>
>> Jiri
> 
> Oh?  I'm sitting here watching the tty0 screen of my lappy after x has 
> been started, and I have established a connection, but SoftMAC is still 
> logging its scan activity, starting with channel 1 and scanning 14 
> channels.  Its doing this at approximately 2 minute intervals.  So I 
> think we have your definition of a clear bug and misbehaviour.
> 

Are you running NetworkManager? If so, that is the source of the scanning.

Larry

Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Dan Williams]

On Thu, 2007-01-25 at 09:36 -0600, Larry Finger wrote:
> Gene Heskett wrote:
> > On Thursday 25 January 2007 07:50, Jiri Benc wrote:
> >> On Thu, 25 Jan 2007 12:47:08 +0100, Ivo Van Doorn wrote:
> >>> Correct, similar problems have been detected in rt2x00. The temporary
> >>> solution in there is to demand a scanning operation after the
> >>> interface has been brought up.
> >> Scanning? No no no, please! That would be a clear bug and misbehaviour.
> >>
> >> Jiri
> > 
> > Oh?  I'm sitting here watching the tty0 screen of my lappy after x has 
> > been started, and I have established a connection, but SoftMAC is still 
> > logging its scan activity, starting with channel 1 and scanning 14 
> > channels.  Its doing this at approximately 2 minute intervals.  So I 
> > think we have your definition of a clear bug and misbehaviour.
> > 
> 
> Are you running NetworkManager? If so, that is the source of the scanning.

Right; and NM scans at 2m intervals by default, unless you've clicked
the menu (or a few other instances) where it will jump up to 20s and
then back off to 2m again.

dan


> Larry
> 
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Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[Michael Wu]

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On Thursday 25 January 2007 01:50, Pavel Roskin wrote:
> If the hardware drivers are supposed to do it, here's my patch.  It is
> working fine for me and ready to be applied.  The changelog is in the
> subject.
Let's fix this in the stack. This problem will be fixed for most users once 
auto channel selection is implemented, and fixing it for users manually 
setting the channel should be trivial.

-Michael Wu

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Re: [RFC PATCH] bcm43xx: set channel when the interface is brought up

[John W. Linville]

On Thu, Jan 25, 2007 at 11:51:27AM -0500, Michael Wu wrote:
> On Thursday 25 January 2007 01:50, Pavel Roskin wrote:
> > If the hardware drivers are supposed to do it, here's my patch.  It is
> > working fine for me and ready to be applied.  The changelog is in the
> > subject.
> Let's fix this in the stack. This problem will be fixed for most users once 
> auto channel selection is implemented, and fixing it for users manually 
> setting the channel should be trivial.

ACK...fixing the stack makes the most sense.

-- 
John W. Linville
linville@tuxdriver.com