[Fire HD 8 and HD 10 Original Android Development] SergeantFury:
I'm increasingly less sure that we're suffering from the same issue. My 5GHz SSID is visible to the tablet and it allows me to type in a password, but it refused to connect (repeatedly fails on "Establishing connection") until I put in the patched kernel.

In other news, I wiped /system from TWRP and reflashed my ROM and boot image and it seems to be working again. At least that's consistent.

I checked iw list from the now-able-to-connect tablet and it also appears to be restricted:

karnak:/ # iw list
Wiphy phy1
max # scan SSIDs: 1
max scan IEs length: 512 bytes
max # sched scan SSIDs: 0
max # match sets: 0
Retry short limit: 7
Retry long limit: 4
Coverage class: 0 (up to 0m)
Supported Ciphers:
* WEP40 (00-0f-ac:1)
* WEP104 (00-0f-ac:5)
* TKIP (00-0f-ac:2)
* CCMP (00-0f-ac:4)
* CMAC (00-0f-ac:6)
Available Antennas: TX 0 RX 0
Supported interface modes:
* managed
* AP
* P2P-client
* P2P-GO
Band 1:
Capabilities: 0x7e
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
No RX STBC
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-7
Bitrates (non-HT):
* 1.0 Mbps
* 2.0 Mbps
* 5.5 Mbps
* 11.0 Mbps
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
Frequencies:
* 2412 MHz [1] (30.0 dBm)
* 2417 MHz [2] (30.0 dBm)
* 2422 MHz [3] (30.0 dBm)
* 2427 MHz [4] (30.0 dBm)
* 2432 MHz [5] (30.0 dBm)
* 2437 MHz [6] (30.0 dBm)
* 2442 MHz [7] (30.0 dBm)
* 2447 MHz [8] (30.0 dBm)
* 2452 MHz [9] (30.0 dBm)
* 2457 MHz [10] (30.0 dBm)
* 2462 MHz [11] (30.0 dBm)
* 2467 MHz [12] (disabled)
* 2472 MHz [13] (disabled)
* 2484 MHz [14] (disabled)
Band 2:
Capabilities: 0x7e
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
No RX STBC
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-7
Bitrates (non-HT):
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
Frequencies:
* 5170 MHz [34] (disabled)
* 5180 MHz [36] (23.0 dBm)
* 5190 MHz [38] (disabled)
* 5200 MHz [40] (23.0 dBm)
* 5210 MHz [42] (disabled)
* 5220 MHz [44] (23.0 dBm)
* 5230 MHz [46] (disabled)
* 5240 MHz [48] (23.0 dBm)
* 5260 MHz [52] (disabled)
* 5280 MHz [56] (disabled)
* 5300 MHz [60] (disabled)
* 5320 MHz [64] (disabled)
* 5500 MHz [100] (disabled)
* 5520 MHz [104] (disabled)
* 5540 MHz [108] (disabled)
* 5560 MHz [112] (disabled)
* 5580 MHz [116] (disabled)
* 5600 MHz [120] (disabled)
* 5620 MHz [124] (disabled)
* 5640 MHz [128] (disabled)
* 5660 MHz [132] (disabled)
* 5680 MHz [136] (disabled)
* 5700 MHz [140] (disabled)
* 5745 MHz [149] (30.0 dBm)
* 5765 MHz [153] (30.0 dBm)
* 5785 MHz [157] (30.0 dBm)
* 5805 MHz [161] (30.0 dBm)
* 5825 MHz [165] (30.0 dBm)
* 5845 MHz [169] (disabled)
* 5865 MHz [173] (disabled)
* 5920 MHz [184] (disabled)
* 5940 MHz [188] (disabled)
* 5960 MHz [192] (disabled)
* 5980 MHz [196] (disabled)
* 6000 MHz [200] (disabled)
* 6020 MHz [204] (disabled)
* 6040 MHz [208] (disabled)
* 6060 MHz [212] (disabled)
* 6080 MHz [216] (disabled)
Supported commands:
* set_interface
* new_key
* start_ap
* set_bss
* deauthenticate
* disassociate
* join_ibss
* remain_on_channel
* set_tx_bitrate_mask
* frame
* set_channel
* testmode
* connect
* disconnect
Supported TX frame types:
* IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
Supported RX frame types:
* IBSS: 0xd0
* managed: 0x40 0xd0
* AP: 0x40 0xd0
* AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
* P2P-client: 0x40 0xd0
* P2P-GO: 0x40 0xd0
WoWLAN support:
* wake up on anything (device continues operating normally)
* wake up on disconnect
software interface modes (can always be added):
valid interface combinations:
* #{ managed, AP, P2P-client, P2P-GO } <= 2,
total <= 2, #channels <= 2
Device supports scan flush.
Wiphy phy0
max # scan SSIDs: 4
max scan IEs length: 512 bytes
max # sched scan SSIDs: 4
max # match sets: 16
Retry short limit: 7
Retry long limit: 4
Coverage class: 0 (up to 0m)
Device supports roaming.
Device supports T-DLS.
Supported Ciphers:
* WEP40 (00-0f-ac:1)
* WEP104 (00-0f-ac:5)
* TKIP (00-0f-ac:2)
* CCMP (00-0f-ac:4)
* CMAC (00-0f-ac:6)
Available Antennas: TX 0 RX 0
Supported interface modes:
* IBSS
* managed
* P2P-client
Band 1:
Capabilities: 0x7e
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
No RX STBC
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-7
Bitrates (non-HT):
* 1.0 Mbps
* 2.0 Mbps
* 5.5 Mbps
* 11.0 Mbps
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
Frequencies:
* 2412 MHz [1] (30.0 dBm)
* 2417 MHz [2] (30.0 dBm)
* 2422 MHz [3] (30.0 dBm)
* 2427 MHz [4] (30.0 dBm)
* 2432 MHz [5] (30.0 dBm)
* 2437 MHz [6] (30.0 dBm)
* 2442 MHz [7] (30.0 dBm)
* 2447 MHz [8] (30.0 dBm)
* 2452 MHz [9] (30.0 dBm)
* 2457 MHz [10] (30.0 dBm)
* 2462 MHz [11] (30.0 dBm)
* 2467 MHz [12] (disabled)
* 2472 MHz [13] (disabled)
* 2484 MHz [14] (disabled)
Band 2:
Capabilities: 0x7e
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
No RX STBC
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-7
Bitrates (non-HT):
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
Frequencies:
* 5170 MHz [34] (disabled)
* 5180 MHz [36] (23.0 dBm)
* 5190 MHz [38] (disabled)
* 5200 MHz [40] (23.0 dBm)
* 5210 MHz [42] (disabled)
* 5220 MHz [44] (23.0 dBm)
* 5230 MHz [46] (disabled)
* 5240 MHz [48] (23.0 dBm)
* 5260 MHz [52] (disabled)
* 5280 MHz [56] (disabled)
* 5300 MHz [60] (disabled)
* 5320 MHz [64] (disabled)
* 5500 MHz [100] (disabled)
* 5520 MHz [104] (disabled)
* 5540 MHz [108] (disabled)
* 5560 MHz [112] (disabled)
* 5580 MHz [116] (disabled)
* 5600 MHz [120] (disabled)
* 5620 MHz [124] (disabled)
* 5640 MHz [128] (disabled)
* 5660 MHz [132] (disabled)
* 5680 MHz [136] (disabled)
* 5700 MHz [140] (disabled)
* 5745 MHz [149] (30.0 dBm)
* 5765 MHz [153] (30.0 dBm)
* 5785 MHz [157] (30.0 dBm)
* 5805 MHz [161] (30.0 dBm)
* 5825 MHz [165] (30.0 dBm)
* 5845 MHz [169] (disabled)
* 5865 MHz [173] (disabled)
* 5920 MHz [184] (disabled)
* 5940 MHz [188] (disabled)
* 5960 MHz [192] (disabled)
* 5980 MHz [196] (disabled)
* 6000 MHz [200] (disabled)
* 6020 MHz [204] (disabled)
* 6040 MHz [208] (disabled)
* 6060 MHz [212] (disabled)
* 6080 MHz [216] (disabled)
Supported commands:
* set_interface
* new_key
* new_station
* associate
* join_ibss
* set_pmksa
* del_pmksa
* flush_pmksa
* remain_on_channel
* frame
* tdls_mgmt
* tdls_oper
* start_sched_scan
* testmode
* connect
* disconnect
Supported TX frame types:
* IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
Supported RX frame types:
* IBSS: 0xd0
* managed: 0x40 0xd0
* AP: 0x40 0xd0
* AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
* P2P-client: 0x40 0xd0
* P2P-GO: 0x40 0xd0
WoWLAN support:
* wake up on anything (device continues operating normally)
* wake up on disconnect
software interface modes (can always be added):
valid interface combinations:
* #{ IBSS, managed, P2P-client } <= 2,
total <= 2, #channels <= 2
Device supports scan flush.