BCM43602 Macs only see 2.4 GHz Wi-Fi out of the box

[shawnyeager]

2015–2017 Intel Macs with Broadcom BCM43602 (14e4:43ba) associate fine on 2.4 GHz under brcmfmac, but never list or join 5 GHz networks. linux-firmware-broadcom ships the chip firmware and no board calibration file, so the driver loads with placeholder 5 GHz values (aa5g=1, no per-channel tx-power tables) and iw phy only advertises Band 1.

Verified on MacBookPro14,3 (same chip as MacBookPro14,2):

• Before: associated on 2437 MHz (ch 6), -66 dBm, 104 / 144 Mbit/s, scan is 2.4 GHz only
• After installing a calibrated NVRAM and rebooting: 5745 MHz (ch 149), -40 dBm, 867 / 650 Mbit/s, Band 2 present, dual-band APs listed on both frequencies

Kernel log on the broken path:

brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43602-pcie for chip BCM43602/2
brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available
brcmfmac: brcmf_c_process_txcap_blob: no txcap_blob available (err=-2)

Fix

PR: #7671

Credit

The field recipe this follows is @csk-grit42's HOWTO-wifi.md in OmarchyOnMacBookPro14.2-2017---A1706-. That write-up identified the missing BCM43602 NVRAM (kernel.org bugzilla attachment 290569) and the host regulatory-domain handoff that unlocks 5 GHz on these Macs.

[nanwangjkl]

Additional report: MacBookPro12,1 sees upper 5 GHz channels but not channels 36–64

I am seeing a related but slightly different BCM43602 issue on a 2015 MacBook Pro.

Hardware

• Model: Apple MacBookPro12,1
• Board: Mac-E43C1C25D4880AD6
• Wireless chipset: Broadcom BCM43602
• PCI ID: 14e4:43ba
• Subsystem: 106b:0133
• Driver: brcmfmac

No MAC addresses, BSSIDs, IP addresses, or private SSIDs are included in this report.

Software

• Omarchy: 4.0.0-1
• Kernel: 7.1.8-arch1-3
• NetworkManager: 1.58.0-1
• wpa_supplicant: 2.12
• Firmware package: linux-firmware-broadcom 20260810-2
• Loaded firmware:

BCM43602/1
Firmware version 7.35.177.61 (r598657)
FWID 01-ea662a8c

Kernel messages

brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43602-pcie for chip BCM43602/1
brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available
brcmfmac: brcmf_c_process_txcap_blob: no txcap_blob available (err=-2)
brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43602/1 wl0: Nov 10 2015 06:38:10 version 7.35.177.61 (r598657) FWID 01-ea662a8c

Wireless capabilities

iw phy reports both 2.4 GHz and 5 GHz bands.

The following 5 GHz channels are advertised as enabled:

36, 40, 44, 48
52, 56, 60, 64 (radar detection)
149, 153, 157, 161, 165

The device supports 80 MHz but not 160 MHz or 80+80 MHz:

Supported Channel Width: neither 160 nor 80+80
short GI (80 MHz)

Actual behavior

The adapter works normally on 2.4 GHz.

It also successfully scans 5 GHz access points on upper-band channels, including:

149
157
161

However, it cannot see my own 5 GHz access point when it operates on either:

Channel 60 / 5300 MHz
Channel 44 / 5220 MHz

The SSID does not appear in NetworkManager, even after a targeted rescan:

nmcli device wifi rescan ifname wlp3s0 ssid <REDACTED>
nmcli device wifi list ifname wlp3s0

A privileged direct passive scan on channel 44 also receives no BSS from that access point:

iw dev wlp3s0 scan freq 5220 passive

This rules out NetworkManager filtering the result.

Access-point tests

The access point uses a MediaTek MT7986-series radio and supports:

802.11a/n/ac/ax

I tested these configurations:

1. Channel 60 with 160 MHz width
2. Channel 60 with 80 MHz width
3. Channel 44 with 80 MHz width

The BCM43602 could not see the SSID in any configuration.

After changing the width on channel 60, I waited beyond the DFS CAC period and repeated the scan. The SSID remained absent.

The access point is visible and usable from:

• Multiple phones
• A Windows installation

Those devices continued to see the network on channel 44, confirming that the access point was broadcasting correctly.

Expected behavior

Because iw phy advertises channels 44 and 60 as supported, and because the AP offers legacy 802.11a/n/ac compatibility, the BCM43602 should at least discover the SSID.

Important distinction from the original report

This machine is not completely limited to 2.4 GHz. It can discover upper-band 5 GHz networks on channels 149–161.

The apparent limitation is specifically that it cannot discover lower 5 GHz channels 36–64, despite those channels being advertised by iw phy.

NVRAM concern

The proposed NVRAM in PR #7671 is currently restricted to MacBookPro14,2 and MacBookPro14,3. I have not installed it because calibration data is board-specific, and this
machine is a MacBookPro12,1 with subsystem 106b:0133.

A model-appropriate NVRAM/calibration source may be required. It would be useful to determine whether:

1. MacBookPro12,1 requires its own board-specific BCM43602 NVRAM;
2. missing calibration data can explain upper-band-only 5 GHz discovery;
3. there is a safe method to extract the original calibration data from Apple firmware or EFI;
4. this model should receive a separate, explicitly tested fix rather than reusing the MacBookPro14,2/14,3 data.

I can provide additional sanitized command output or test a model-specific, reversible fix if needed.