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
