PCIe adapter fails after hours of uptime
A Linux user found that the wireless connection failed after anywhere from fifteen minutes to many hours of uptime, on both the distribution kernel and several upstream release candidates, with PCI errors in the log.
The first suggestion from a developer was to switch off station power-save mode with the standard wireless configuration tool and see whether the failure stopped. The user's access point had no power-saving setting to change.
Takeaway. Disable client power save first when a link dies after idling. If it still fails, collect the kernel log from the moment of failure.