On 20/01/2023 16:55, Lorenzo Bianconi wrote:
On 19/01/2023 15:02, Johannes Berg wrote:
On Mon, 2022-12-26 at 14:03 +0530, Rameshkumar Sundaram wrote:
As per 802.11ax-2021, STAs shall process BSS Color Change Announcement
(BCCA) from AP and switch to new color, but some STAs aren't processing
BCCA from AP and not doing color switch, causing them to drop data
frames from AP post color change.
Provide an option to disable color collision detection and therefore
not to do BCCA to mitigate the same from AP. If it's required in case
where STA supports BCCA handling, then it can enabled in AP using this
option.
You should probably split this into cfg80211 and mac80211.
Also, this doesn't really seem to make a lot of _sense_ since nothing in
the kernel actually acts on detection of a color collision - hostapd is
acting on that.
So since you can easily make hostapd ignore the event, why do you even
need this?
This may not be related, but the software color collision detection sends a
netlink message for every colliding frame and it can hose up the system if
the other network is very active.
Also, cfg80211_bss_color_notify() complains that the wdev lock isn't held.
Hi Nicolas,
I agree, I think we can ratelimit netlink messages sent by the kernel to
userspace (e.g. to hostapd), I would say every 500ms is ok.
I guess we can move cfg80211_obss_color_collision_notify() in a dedicated
delayed_work so we can grab wdev mutex (cfg80211_obss_color_collision_notify is
currently running in interrupt context).
To give an idea, what do you think about patch below? (please note it is just
compiled tested so far).
I think it should fix the problem, I'll try to test it.
Thanks!
Regards,
Lorenzo
