Messages in this thread | | | Date | Tue, 19 Jul 2022 17:36:33 +0200 | Subject | Re: [PATCH] mac80211: Fix wrong channel bandwidths reported for aggregates | From | Linus Lüssing <> |
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On 19/07/2022 17:03, Adrian Chadd wrote: > Hi! > > It's not a hardware bug. Dating back to the original AR5416 11n chip, > most flags aren't valid for subframes in an aggregate. Only the final > frame has valid flags. This was explicitly covered internally way back > when.
Ah, thanks for the clarification! I see it in the datasheet for the QCA9531, too, now. And thanks for the confirmation, that what we are doing so far is not correct for ath9k.
Words 0+2 are valid for all RX descriptors, 0+2+11 valid for the last RX descriptor of each packet and 0-11 for the last RX descriptor of an aggregate or last RX descriptor of a stand-alone packet. Or in other words, word 4, which contains the 20 vs. 40 MHz indicator, is invalid for any aggregate sub-frame other than the last one. I can rename that in the commit message.
Another approach that also came to my mind was introducing more explicit flags in cfg80211.h's "struct rate_info", like a RATE_INFO_BW_UNKNOWN in "enum rate_info_bw" and/or RATE_INFO_FLAGS_UNKNOWN in "enum rate_info_flags". And setting those flags in ath9k_cmn_process_rate().
The current approach is smaller though, as it simply uses the already existing flags. If anyone has any preferences, please let me know.
Regards, Linus
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