This test is failing for devices setups having 
1) 8897 MRVL (3.14 kernel version)  and  Whirlwind router
           Veyron_Fievel
           Veyron_Mighty
           Daisy (chromeos2-row11-rack3-host4). 
 Association is failing on Channel 1. network_WiFi_VerifyRouter passes if we run it specifically for channel 1.  Here is the output for 
 network_WiFi_VerifyRouter  on Veyron_Fievel (+whirlwind)

-------------------------------------------------------------------------------------------------------
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter                           [  PASSED  ]
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter [  PASSED  ]
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_0_bm_1_ch_1                                                                 -47
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_0_bm_2_ch_1                                                                 -29
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_0_bm_3_ch_1                                                                 -30
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_1_bm_1_ch_1                                                                 -48
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_1_bm_2_ch_1                                                                 -29
/tmp/test_that_results_LYKCf2/results-1-network_WiFi_VerifyRouter/network_WiFi_VerifyRouter   signal_for_ap_1_bm_3_ch_1                                                                 -30
-------------------------------------------------------------------------------------------------------
Total PASS: 2/2 (100%)


2)The devices with same chipset and kernel version using  Stumpy router do not see this issue.  
 For example, 
           Daisy (chromeos2-row11-rack2-host)
           Veyron_Jaq (chromeos2-row11-rack1-host4)


Veyron_Mighty using stumpy is not running any test. Created a separate bug to track it. 
Buganizer link: http://b/111085854

Should we move the Daisy, Fievel setups to Stumpy router or debug for whirlwind setups?

Testcases failing on devices Daisy, Veyron_Mighty, Veyron_Fievel:

1)network_WiFi_SimpleConnect.wifi_check1x_WPA Debugging. 
2)network_WiFi_MultiAuth

More testcases failing with same error:
3)network_WiFi_SimpleConnect.wifi_checkWPA_multi
4)network_WiFi_SimpleConnect.wifi_check1x_PEAP
5)network_WiFi_SimpleConnect.wifi_check1x_TTLS
6)network_WiFi_SimpleConnect.wifi_checkWPA_CCMP
7)network_WiFi_SimpleConnect.wifi_checkWPA_TKIP
8)network_WiFi_SimpleConnect.wifi_checkOddWPAPassphrases
9)network_WiFi_SimpleConnect.wifi_checkRawPMK

As mentioned, majority of the association time out failures are occurring on daisy, fievel, mighty and tiger along with speedy and lars at a lower frequency. All of these are with whirlwind routers.

https://stainless.corp.google.com/search?view=matrix&row=board_model&col=hostname&owner=%5Echromeos%5C-test%24&test=%5Enetwork_WiFi_SimpleConnect&model=daisy%7Cveyron_mighty%7Cveyron_fievel%7Cveyron_tiger&status=GOOD&status=FAIL&status=ABORT&status=TEST_NA&reason=Association+timed+out&exclude_cts=true&exclude_not_run=false&exclude_non_release=true&exclude_au=true&exclude_acts=true&exclude_retried=true&exclude_non_production=false&days=45


From the logs it looks like the AP gets configured as expected and I don't see any issue with signal strength. Example log links below...

autoserve logs: https://storage.cloud.google.com/chromeos-autotest-results/212291885-chromeos-test/chromeos15-row1-rack8-host4/debug/autoserv.DEBUG

hostapd logs: https://storage.cloud.google.com/chromeos-autotest-results/212291885-chromeos-test/chromeos15-row1-rack8-host4/network_WiFi_SimpleConnect.wifi_check1x_WPA/debug/hostapd_router_0_managed0.log

I didn't check many different failures yet, but at least one checkWPA_multi failure is because mwifiex is rejecting the configuration (in syslog -- look for the 'messages' file in sysinfo):

2018-06-27T14:18:36.471500+00:00 INFO shill_xmlrpc_server[6253]: [INFO] Associating...
2018-06-27T14:18:36.483460+00:00 ERR kernel: [ 6430.084908] mwifiex_sdio mmc2:0001:1: Incompatible network settings



It's possible you could get better info if you turned up the mwifiex logging.