Add workaround for BCM4377b Wi-Fi failing after lid close#688
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herzj-tcd wants to merge 2 commits intot2linux:masterfrom
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Add workaround for BCM4377b Wi-Fi failing after lid close#688herzj-tcd wants to merge 2 commits intot2linux:masterfrom
herzj-tcd wants to merge 2 commits intot2linux:masterfrom
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Add BCM4377b lid close Wi-Fi fix
AdityaGarg8
reviewed
Mar 8, 2026
| ``` | ||
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| !!! Warning "Do not unload the module pre-suspend" | ||
| Unloading `brcmfmac` before suspend (e.g. with `modprobe -r`) causes a hard crash on |
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This is weird. I've seen many people simply unloading and suspending.
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| known Broadcom firmware bug [reported to Broadcom](https://github.com/t2linux/T2-Debian-and-Ubuntu-Kernel/issues) | ||
| with no upstream fix available. The workaround below resolves it. |
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I think you used the wrong link here
| `GRUB_CMDLINE_LINUX_DEFAULT`, then update GRUB: | ||
| ```bash | ||
| sudo update-grub | ||
| ``` |
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This is not the correct way to change kernel parameters on all distros. On Fedora you should use grubby --args="mem_sleep_default=s2idle" --update-kernel=ALL, and some people with arch use systemd-boot which means you have to edit /etc/kernel/cmdline and then regenerate the BLS files.
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Adds documentation for a known issue on T2 Macs with the BCM4377b Wi-Fi chip (confirmed on MacBookAir9,1) where brcmfmac fails to enter D3 power state during suspend, leaving Wi-Fi and Bluetooth unresponsive after the lid is opened.
The root cause is a Broadcom firmware bug that has been reported upstream but has no fix available. The workaround involves forcing s2idle sleep and using a post-resume systemd script to rebind the driver and reload the firmware.