PCIe recovery mechanism

Avinash Patil avinashapatil at gmail.com
Thu Jan 8 23:49:15 EST 2015


Hello,

I was wondering if there is any way to recover from FW crash in case
of WLAN PCie cards- say we power off card and power on. This would
enable hotplug to detect it again and driver's probe routine would do
redownload of FW and device is alive again.

1. I went through PCI bus driver sources and came across
pci_set_power_state which can be used to set PCI power state to
D0-D3hot/D3cold. Suppose we set power state to D3Cold, I dont think
dev pointer would be valid again to set to D0.

2. Another idea is something similar to PCI rescan operation via
sysfs(echo 1 > /sys/bus/pci/rescan). I am not entirely sure though if
this can be applied to single device as this involves scanning all
devices on PCI bus.

Any help appreciated!

Thanks,
Avinash



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