Creating mesh in TP link archer c6 using cli

I am trying to create a un encrypted mesh in TP link archer c6 router. I followed the steps given in the openwrt website (https://openwrt.org/docs/guide-user/network/wifi/mesh/80211s). After following the given steps when I tried to bring up the mesh interface I get an error Network is down (-127).
I edited the wireless configuration file as given in the documentation...What can the problem be ? How to overcome this?

Does iw phy indicate that your wireless chip(s) and driver(s) support mesh?

If not, you may need to use the ath10k (no -ct) drivers for that chip or chips.

Thanks a lot for reply!

root@OpenWrt:~# iw phy
Wiphy phy1
	max # scan SSIDs: 4
	max scan IEs length: 2257 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 0 (up to 0m)
	Device supports AP-side u-APSD.
	Device supports T-DLS.
	Available Antennas: TX 0x7 RX 0x7
	Configured Antennas: TX 0x7 RX 0x7
	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
		 * mesh point
		 * P2P-client
		 * P2P-GO
		 * outside context of a BSS
	Band 1:
		Capabilities: 0x11ee
			HT20/HT40
			SM Power Save disabled
			RX HT20 SGI
			RX HT40 SGI
			TX STBC
			RX STBC 1-stream
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 8 usec (0x06)
		HT TX/RX MCS rate indexes supported: 0-23
		Frequencies:
			* 2412 MHz [1] (22.0 dBm)
			* 2417 MHz [2] (22.0 dBm)
			* 2422 MHz [3] (22.0 dBm)
			* 2427 MHz [4] (22.0 dBm)
			* 2432 MHz [5] (22.0 dBm)
			* 2437 MHz [6] (22.0 dBm)
			* 2442 MHz [7] (22.0 dBm)
			* 2447 MHz [8] (22.0 dBm)
			* 2452 MHz [9] (22.0 dBm)
			* 2457 MHz [10] (22.0 dBm)
			* 2462 MHz [11] (22.0 dBm)
			* 2467 MHz [12] (disabled)
			* 2472 MHz [13] (disabled)
			* 2484 MHz [14] (disabled)
	valid interface combinations:
		 * #{ managed } <= 2048, #{ AP, mesh point } <= 8, #{ P2P-client, P2P-GO } <= 1, #{ IBSS } <= 1,
		   total <= 2048, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz }

	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
	Supported extended features:
		* [ RRM ]: RRM
		* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
		* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
		* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
Wiphy phy0
	max # scan SSIDs: 16
	max scan IEs length: 199 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 0 (up to 0m)
	Device supports AP-side u-APSD.
	Device supports T-DLS.
	Available Antennas: TX 0x3 RX 0x3
	Configured Antennas: TX 0x3 RX 0x3
	Supported interface modes:
		 * managed
		 * AP
		 * monitor
		 * mesh point
	Band 2:
		Capabilities: 0x19ef
			RX LDPC
			HT20/HT40
			SM Power Save disabled
			RX HT20 SGI
			RX HT40 SGI
			TX STBC
			RX STBC 1-stream
			Max AMSDU length: 7935 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 8 usec (0x06)
		HT TX/RX MCS rate indexes supported: 0-15
		VHT Capabilities (0x339979b2):
			Max MPDU length: 11454
			Supported Channel Width: neither 160 nor 80+80
			RX LDPC
			short GI (80 MHz)
			TX STBC
			SU Beamformer
			SU Beamformee
			MU Beamformer
			MU Beamformee
			RX antenna pattern consistency
			TX antenna pattern consistency
		VHT RX MCS set:
			1 streams: MCS 0-9
			2 streams: MCS 0-9
			3 streams: not supported
			4 streams: not supported
			5 streams: not supported
			6 streams: not supported
			7 streams: not supported
			8 streams: not supported
		VHT RX highest supported: 0 Mbps
		VHT TX MCS set:
			1 streams: MCS 0-9
			2 streams: MCS 0-9
			3 streams: not supported
			4 streams: not supported
			5 streams: not supported
			6 streams: not supported
			7 streams: not supported
			8 streams: not supported
		VHT TX highest supported: 0 Mbps
		Frequencies:
			* 5180 MHz [36] (23.0 dBm)
			* 5200 MHz [40] (23.0 dBm)
			* 5220 MHz [44] (23.0 dBm)
			* 5240 MHz [48] (23.0 dBm)
			* 5260 MHz [52] (23.0 dBm) (radar detection)
			* 5280 MHz [56] (23.0 dBm) (radar detection)
			* 5300 MHz [60] (23.0 dBm) (radar detection)
			* 5320 MHz [64] (23.0 dBm) (radar detection)
			* 5500 MHz [100] (23.0 dBm) (radar detection)
			* 5520 MHz [104] (23.0 dBm) (radar detection)
			* 5540 MHz [108] (23.0 dBm) (radar detection)
			* 5560 MHz [112] (23.0 dBm) (radar detection)
			* 5580 MHz [116] (23.0 dBm) (radar detection)
			* 5600 MHz [120] (23.0 dBm) (radar detection)
			* 5620 MHz [124] (23.0 dBm) (radar detection)
			* 5640 MHz [128] (23.0 dBm) (radar detection)
			* 5660 MHz [132] (23.0 dBm) (radar detection)
			* 5680 MHz [136] (23.0 dBm) (radar detection)
			* 5700 MHz [140] (23.0 dBm) (radar detection)
			* 5720 MHz [144] (23.0 dBm) (radar detection)
			* 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)
	valid interface combinations:
		 * #{ managed } <= 1, #{ AP, mesh point } <= 16,
		   total <= 16, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz, 80 MHz, 80+80 MHz, 160 MHz }

	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
	Supported extended features:
		* [ VHT_IBSS ]: VHT-IBSS
		* [ RRM ]: RRM
		* [ SET_SCAN_DWELL ]: scan dwell setting
		* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
		* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
		* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs

This is the output I have got when I ran iw phy, It shows I have an option for mesh point support in both phy0 and phy1 which means I have chips that support for mesh but how to check driver support?
Currently I'm using (https://github.com/kvalo/ath10k-firmware/tree/master/QCA9888/hw2.0/3.6) firmware given here.

At least as far as I understand it, iw phy queries the driver/firmware combination for capabilities. So, between

	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
		 * mesh point

and

	valid interface combinations:
		 * #{ managed } <= 2048, #{ AP, mesh point } <= 8,

it looks like you're in good shape to me.

Somewhat confusing is that for an encrypted 802.11 mesh (when you get to that point), wpad-mesh needs to be installed, not wpad-full.

I didn't see your wireless-config stanza, but here's a redacted and annotated version of one of my encrypted mesh interfaces

config wifi-device 'radio5'           # I explicitly name my wifi-devices so I can more easily maintain my config
        option type 'mac80211'
        [...]

config wifi-iface 'mesh0'
        option device 'radio5' 
        option ifname 'mesh0'         # Same for "raw" interface naming
        option network 'nwi_mesh0'    # Which OpenWrt-defined interface will this associate with
        option mode 'mesh'            # Sets 802.11s operation
        option mesh_id 'Test Mesh'    # Naming of your choice
        option mesh_fwding '0'        # Disables 802.11s routing (as I run batman-adv on this mesh)
        option encryption 'psk2+ccmp'
        option key 'Not a secret anymore!'

Perhaps obvious, but all the mesh participants need to be on the same channel, with the same mesh_id and, if encrypted, the same encryption and key