Re: [PATCH] rtl8xxxu: Enable data frame reception in rtl8xxxu_start

[Bruno Randolf <br1@thinktube.com>]

On 10/22/2015 12:13 AM, Jes Sorensen wrote:
> Bruno Randolf <br1@einfach.org> writes:
>> mac80211 documentation says, the ieee80211_ops.start callback "must turn on
>> frame reception (for possibly enabled monitor interfaces.)". If not a single
>> monitor interface does not receive data frames.
>>
>> Similarly we should not change the data reception based on the association
>> state.
>>
>> Signed-off-by: Bruno Randolf <br1@einfach.org>
>> ---
>>  drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c | 12 ++----------
>>  1 file changed, 2 insertions(+), 10 deletions(-)
> 
> Bruno,
> 
> Thanks - I am not 100% convinced about this one. I don't think we should
> tell the firmware to pass up data frames before we have negotiated the
> connection.
> 
> It's true that for monitor mode, we need to enable it if all packets
> are requested. Looking at iw there is an option where it only requests
> control packets, and one for all, etc. However for non monitor mode, we
> shouldn't pass all data packets up to the stack, resulting and have
> mac80211 parse them all.

But mac80211 requests us to do so - please see include/net/mac80211.h
line 2576 or
https://www.kernel.org/doc/htmldocs/80211/API-struct-ieee80211-ops.html

I know you are focusing on STA mode at the moment, but
enabling/disabling data reception on association is not correct for most
other modes.

Also don't be afraid of too many frames being passed. In the initial
setting (without a monitor interface) the RCR RCR_ACCEPT_AP bit is not
set and the RCR_CHECK_BSSID_* bits are set as well.

bruno