Trouble shooting low rate MCS9 in 802.11ac

[Vu Hai NGUYEN]

>> I follow a tutorial to cross compile perf so here is my result
>>
>>
>> PerfTop:      70 irqs/sec  kernel:98.6%  exact:  0.0% [1000Hz cycles],  (all, 1 CPU)
>> -------------------------------------------------------------------------------
>>
>>     39.43%  [kernel]       [k] csum_partial_copy_nocheck

>Looks like your ethernet driver is not doing checksum offloading?

>I am pretty sure ath10k does support this unless you have managed
>to disabled it somehow?

I'm using ath10k from master branch (generated by backport), My only hack is changing the default country of regulatory domain from US to France.
The checksum patch is implemented by Michal Kazior since july 2013 and I also check that there is function checksum state in htt_rx.c file so it should be in my 
driver module.
But I install ethtool and here is the ouput of my interface wlan0:
#ethtool --show-offload  wlan0 
Features for wlan0:
rx-checksumming: off [fixed]
tx-checksumming: on
	tx-checksum-ipv4: off [fixed]
	tx-checksum-unneeded: off [fixed]
	tx-checksum-ip-generic: on [fixed]
	tx-checksum-ipv6: off [fixed]
	tx-checksum-fcoe-crc: off [fixed]
	tx-checksum-sctp: off [fixed]
scatter-gather: off
	tx-scatter-gather: off [fixed]
	tx-scatter-gather-fraglist: off [fixed]
tcp-segmentation-offload: off
	tx-tcp-segmentation: off [fixed]
	tx-tcp-ecn-segmentation: off [fixed]
	tx-tcp6-segmentation: off [fixed]
udp-fragmentation-offload: off [fixed]
generic-segmentation-offload: off [requested on]
generic-receive-offload: on
large-receive-offload: off [fixed]
rx-vlan-offload: off [fixed]
tx-vlan-offload: off [fixed]
ntuple-filters: off [fixed]
receive-hashing: off [fixed]
highdma: off [fixed]
rx-vlan-filter: off [fixed]
vlan-challenged: off [fixed]
tx-lockless: off [fixed]
netns-local: on [fixed]
tx-gso-robust: off [fixed]
tx-fcoe-segmentation: off [fixed]
fcoe-mtu: off [fixed]
tx-nocache-copy: on
loopback: off [fixed]

And I cannot enable these function, as it show [fixed] like above.
# ethtool --offload  wlan0  rx on  tx on
Cannot change rx-checksumming
Cannot change tx-checksumming


>>      5.54%  [kernel]       [k] __kmalloc_track_caller
>>      4.93%  [kernel]       [k] kfree
>>      4.31%  [mac80211]     [k] ieee80211_tx_status
>>      4.31%  [kernel]       [k] memcpy
>>      3.49%  [kernel]       [k] __memzero
>>      3.29%  [kernel]       [k] mv_eth_poll
>>      3.29%  [kernel]       [k] __kfree_skb
>>      2.05%  [ath10k_pci]   [k] ath10k_ce_send_nolock
>>      1.44%  [mac80211]     [k] $a
>>      1.44%  [kernel]       [k] dev_gro_receive
>>      1.44%  [kernel]       [k] napi_gro_receive
>>      1.44%  [kernel]       [k] eth_type_trans
>>      1.44%  [kernel]       [k] inet_gro_receive
>>      1.44%  [kernel]       [k] skb_copy_and_csum_bits
>>      1.44%  [kernel]       [k] skb_segment
>>      1.44%  [ath10k_core]  [k] ath10k_htt_rx_amsdu_pop
>>      1.44%  [ath10k_core]  [k] ath10k_txrx_tx_unref
>>      1.23%  [kernel]       [k] local_bh_enable
>>      1.23%  [kernel]       [k] kmem_cache_alloc
>>      1.23%  [kernel]       [k] dev_hard_start_xmit
>>
>>
>> Thank you in advance for your response,


NGUYEN Vu Hai
Acita-Sodielec
Route de Mayres - B.P. 9
12100 St GEORGES DE LUZENCON
FRANCE