Firstly, I want to apologize for any mistakes I make this mail.
This is the first mail I have posted
My WiFi chipset:
Qualcomm Atheros AR9380/HB112
Device driver: ath9k (backports-4.1-rc1-1)
In power save multicast transmission, I want to increase the number of transmitted multicast packets at a time.
So, I extend the max_duration of "ath_tx_cabq" function in the file /drivers/net/wireless/ath/ath9k/xmit.c
line 2437 sc->cur_chan->beacon.dtim_period / ATH_BCBUF
=> sc->cur_chan->beacon.dtim_period // Eliminate ATH_BCBUF
Then, multicast packets can be transmitted over one beacon interval. (DTIM interval is not zero)
In this case, some of next multicast packets are transmitted before next DTIM beacon.
(If multicast transmission ends in a beacon interval, all of next multicast packets are transmitted after next DTIM beacon)
For example, if PHY rate for multicast transmission is 6Mb/s, 3 multicast packets are transmitted before DTIM beacon and other packets are transmitted after DTIM beacon.
Is this phenomenon an error of this chipset?
Can I fix this error via modifying device driver?