Pi3 WiFi scan fails after a few days

[tharada]

After running continuously for a few days, my Pi 3 running Raspbian starts refusing to do a WiFi scan. `iw dev wlan0 scan` fails with "Resource temporarily unavailable" and dmesg shows this:

Code: Select all

[259226.270126] brcmfmac: brcmf_cfg80211_escan: Connecting: status (3)
[259226.270148] brcmfmac: brcmf_cfg80211_scan: scan error (-11)

I don't know what triggers the error, but bringing wlan0 down and back up fixes it. If it matters, I'm also running hostapd. Has anyone else seen this behavior? Any ideas on how to prevent it?

Thanks in advance.