I recently did a routine package update on my Fedora 24 laptop. I’ve had the laptop for three years and have been running various Fedorae the whole time, so I didn’t think much of it. So it came as some surprise to me when after rebooting I could no longer connect to my WiFi network. In fact, there was no indication that any wireless networks were even available.
Since the update included a new kernel, I thought that might be the issue. Rebooting into the old kernel seemed to fix it (more on that later!), so I filed a bug, excluded kernel packages from future updates, and moved on.
But a few days later, I rebooted and my WiFi was gone again. The kernel hadn’t updated, so what could it be? I spent a lot of time flailing around until I found a “solution”. A four-year-old forum post said don’t reboot. Booting from off or suspending and resuming the laptop will cause the wireless to work again.
And it turns out, that “fixed” it for me. A few other posts seemed to suggest power management issues in the rt2800pci driver. I guess that’s what’s going on here, though I can’t figure out why I’m suddenly seeing it after so long. Seems like a weird failure mode for failing hardware.
Here’s what dmesg and the systemd journal reported:
Aug 01 14:54:24 localhost.localdomain kernel: ieee80211 phy0: rt2800_wait_wpdma_ready: Error - WPDMA TX/RX busy [0x00000068] Aug 01 14:54:24 localhost.localdomain kernel: ieee80211 phy0: rt2800pci_set_device_state: Error - Device failed to enter state 4 (-5)
Hopefully, this post saves someone else a little bit of time in trying to figure out what’s going on.