2014-05-01 08:26:58

by Arend van Spriel

Subject: net/wireless/chan.c: prohibited_flags wrongly set

Hi Johannes,

I was debugging issue with hostapd failing on setting channel when I
came across this piece of code in chan.c:545:cfg80211_chandef_usable():

if (width > 20)
prohibited_flags |= IEEE80211_CHAN_NO_OFDM;

/* 5 and 10 MHz are only defined for the OFDM PHY */
if (width < 20)
prohibited_flags |= IEEE80211_CHAN_NO_OFDM;

I suspect the first if statement to be wrong, but what should it be?

Regards,
Arend

2014-05-01 20:20:42

by Janusz Dziedzic

Subject: Re: net/wireless/chan.c: prohibited_flags wrongly set

2014-05-01 10:26 GMT+02:00 Arend van Spriel <[email protected]>:
> Hi Johannes,
>
> I was debugging issue with hostapd failing on setting channel when I came
> across this piece of code in chan.c:545:cfg80211_chandef_usable():
>
> if (width > 20)
> prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
>
> /* 5 and 10 MHz are only defined for the OFDM PHY */
> if (width < 20)
> prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
>
> I suspect the first if statement to be wrong, but what should it be?
>
width > 20 - HT40, VHT80 ... - 80211n/80211ac using OFDM - so NO_OFDM
seems to be prohibited.

BR
Janusz