[PATCH] ath6kl: Remove old 802.11a-only channels

[PATCH] ath6kl: Remove old 802.11a-only channels

[Rostyslav Khudolii]

Channels 34/38/42/46 can only be used for compatibility with
old devices sold in Japan. Modern products, such as AR6003/AR6004
don't support these channels.
Keeping them in the upstream is error prone and requires full
network stack support.
A custom patch should be used in case such compatibility is required.

Signed-off-by: Rostyslav Khudolii <rkhudolii@airtame.com>
Cc: Attila Sukosd <attila@airtame.com>
---
 drivers/net/wireless/ath/ath6kl/cfg80211.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c
b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index 363b30a..aae65ce 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -102,10 +102,8 @@ static struct ieee80211_channel ath6kl_2ghz_channels[] = {
 };

 static struct ieee80211_channel ath6kl_5ghz_a_channels[] = {
-       CHAN5G(34, 0), CHAN5G(36, 0),
-       CHAN5G(38, 0), CHAN5G(40, 0),
-       CHAN5G(42, 0), CHAN5G(44, 0),
-       CHAN5G(46, 0), CHAN5G(48, 0),
+       CHAN5G(36, 0), CHAN5G(40, 0),
+       CHAN5G(44, 0), CHAN5G(48, 0),
        CHAN5G(52, 0), CHAN5G(56, 0),
        CHAN5G(60, 0), CHAN5G(64, 0),
        CHAN5G(100, 0), CHAN5G(104, 0),

Re: [PATCH] ath6kl: Remove old 802.11a-only channels

[Johannes Berg]

On Fri, 2017-03-10 at 09:49 +0100, Rostyslav Khudolii wrote:
> Channels 34/38/42/46 can only be used for compatibility with
> old devices sold in Japan. Modern products, such as AR6003/AR6004
> don't support these channels.
> Keeping them in the upstream is error prone and requires full
> network stack support.

Seems pointless. Nothing in the network stack really cares much about
the channel numbers, so what exactly does this improve?

johannes

Re: [PATCH] ath6kl: Remove old 802.11a-only channels

[Rostyslav Khudolii]

On 10 March 2017 at 09:56, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Fri, 2017-03-10 at 09:49 +0100, Rostyslav Khudolii wrote:
>> Channels 34/38/42/46 can only be used for compatibility with
>> old devices sold in Japan. Modern products, such as AR6003/AR6004
>> don't support these channels.
>> Keeping them in the upstream is error prone and requires full
>> network stack support.
>
> Seems pointless. Nothing in the network stack really cares much about
> the channel numbers, so what exactly does this improve?
>

Without this one, a user is able to start an AP using wpa_supplicant,
for example, on one of these channels (34/38/42/46), without getting
any warning/error from the cfg80211 or ath6kl - which is correct
(since these channels match regdom rules). However, the AR6003 and its
firmware (we're using v3.4.0.225) will fail and return
"WMI_CMDERROR_EVENTID" with "INVALID_PARAM" error code.
In my opinion, ath6kl shouldn't support anything the firmware doesn't.
We should also handle WMI_CMDERROR_EVENTID properly (not just printing
a message), but this is another problem, I believe.

Re: [PATCH] ath6kl: Remove old 802.11a-only channels

[Johannes Berg]

On Fri, 2017-03-10 at 10:11 +0100, Rostyslav Khudolii wrote:
> On 10 March 2017 at 09:56, Johannes Berg <johannes@sipsolutions.net>
> wrote:
> > On Fri, 2017-03-10 at 09:49 +0100, Rostyslav Khudolii wrote:
> > > Channels 34/38/42/46 can only be used for compatibility with
> > > old devices sold in Japan. Modern products, such as AR6003/AR6004
> > > don't support these channels.
> > > Keeping them in the upstream is error prone and requires full
> > > network stack support.
> > 
> > Seems pointless. Nothing in the network stack really cares much
> > about
> > the channel numbers, so what exactly does this improve?
> > 
> 
> Without this one, a user is able to start an AP using wpa_supplicant,
> for example, on one of these channels (34/38/42/46), without getting
> any warning/error from the cfg80211 or ath6kl - which is correct
> (since these channels match regdom rules). However, the AR6003 and
> its
> firmware (we're using v3.4.0.225) will fail and return
> "WMI_CMDERROR_EVENTID" with "INVALID_PARAM" error code.
> In my opinion, ath6kl shouldn't support anything the firmware
> doesn't.
> We should also handle WMI_CMDERROR_EVENTID properly (not just
> printing
> a message), but this is another problem, I believe.

Ah. I didn't make the connection that AR6003 was actually a product
that used this driver and thought you were using it as another peer and
then the two couldn't make a connection...

My bad.

johannes

Re: [PATCH] ath6kl: Remove old 802.11a-only channels

[Valo, Kalle]

Johannes Berg <johannes@sipsolutions.net> writes:

> On Fri, 2017-03-10 at 10:11 +0100, Rostyslav Khudolii wrote:
>> On 10 March 2017 at 09:56, Johannes Berg <johannes@sipsolutions.net>
>> wrote:
>> > On Fri, 2017-03-10 at 09:49 +0100, Rostyslav Khudolii wrote:
>> > > Channels 34/38/42/46 can only be used for compatibility with
>> > > old devices sold in Japan. Modern products, such as AR6003/AR6004
>> > > don't support these channels.
>> > > Keeping them in the upstream is error prone and requires full
>> > > network stack support.
>> >=20
>> > Seems pointless. Nothing in the network stack really cares much
>> > about
>> > the channel numbers, so what exactly does this improve?
>> >=20
>>=20
>> Without this one, a user is able to start an AP using wpa_supplicant,
>> for example, on one of these channels (34/38/42/46), without getting
>> any warning/error from the cfg80211 or ath6kl - which is correct
>> (since these channels match regdom rules). However, the AR6003 and
>> its
>> firmware (we're using v3.4.0.225) will fail and return
>> "WMI_CMDERROR_EVENTID" with "INVALID_PARAM" error code.
>> In my opinion, ath6kl shouldn't support anything the firmware
>> doesn't.
>> We should also handle WMI_CMDERROR_EVENTID properly (not just
>> printing
>> a message), but this is another problem, I believe.
>
> Ah. I didn't make the connection that AR6003 was actually a product
> that used this driver and thought you were using it as another peer and
> then the two couldn't make a connection...
>
> My bad.

I'll copy Rostyslav's description above to the commit log, I think it's
useful information to document.

--=20
Kalle Valo=

Re: ath6kl: Remove old 802.11a-only channels

[Kalle Valo]

Rostyslav Khudolii <rkhudolii@airtame.com> wrote:
> Channels 34/38/42/46 can only be used for compatibility with
> old devices sold in Japan. Modern products, such as AR6003/AR6004
> don't support these channels.
> Keeping them in the upstream is error prone and requires full
> network stack support.
> A custom patch should be used in case such compatibility is required.
> 
> Signed-off-by: Rostyslav Khudolii <rkhudolii@airtame.com>
> Cc: Attila Sukosd <attila@airtame.com>

For some reason the patch didn't apply to ath.git, I had manually recreate it.
Please review carefully that the patch is correct now:

https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending&id=cd63adf640e39c2ba013cba91b29700f3f593b9c

Also I added your description of the bug to the commit log.

-- 
https://patchwork.kernel.org/patch/9615199/

Documentation about submitting wireless patches and checking status
from patchwork:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: ath6kl: Remove old 802.11a-only channels

[Rostyslav Khudolii]

On 16 March 2017 at 10:36, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
> Rostyslav Khudolii <rkhudolii@airtame.com> wrote:
>> Channels 34/38/42/46 can only be used for compatibility with
>> old devices sold in Japan. Modern products, such as AR6003/AR6004
>> don't support these channels.
>> Keeping them in the upstream is error prone and requires full
>> network stack support.
>> A custom patch should be used in case such compatibility is required.
>>
>> Signed-off-by: Rostyslav Khudolii <rkhudolii@airtame.com>
>> Cc: Attila Sukosd <attila@airtame.com>
>
> For some reason the patch didn't apply to ath.git, I had manually recreate it.
> Please review carefully that the patch is correct now:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending&id=cd63adf640e39c2ba013cba91b29700f3f593b9c
>
> Also I added your description of the bug to the commit log.
>
> --
> https://patchwork.kernel.org/patch/9615199/
>
> Documentation about submitting wireless patches and checking status
> from patchwork:
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
>

It's correct.

Re: ath6kl: Remove old 802.11a-only channels

[Kalle Valo]

Rostyslav Khudolii <rkhudolii@airtame.com> wrote:
> Channels 34/38/42/46 can only be used for compatibility with old devices sold
> in Japan. Modern products, such as AR6003/AR6004 don't support these channels.
> Keeping them in the upstream is error prone and requires full network stack
> support.  A custom patch should be used in case such compatibility is required.
> 
> Without this one, a user is able to start an AP using wpa_supplicant, for
> example, on one of these channels (34/38/42/46), without getting any
> warning/error from the cfg80211 or ath6kl - which is correct (since these
> channels match regdom rules). However, the AR6003 and its firmware (we're using
> v3.4.0.225) will fail and return "WMI_CMDERROR_EVENTID" with "INVALID_PARAM"
> error code.
> 
> Signed-off-by: Rostyslav Khudolii <rkhudolii@airtame.com>
> Cc: Attila Sukosd <attila@airtame.com>

Patch applied to ath-next branch of ath.git, thanks.

b51040fc375c ath6kl: Remove old 802.11a-only channels

-- 
https://patchwork.kernel.org/patch/9615199/

Documentation about submitting wireless patches and checking status
from patchwork:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches