Reset a PCI Device in Linux

Question

Is there a generic way to reset a PCI device in Linux from the command line? That is, cause the PCI bus to issue a reset command.

Answer 1

The closest thing the PCI bus has to a device level reset is changing the power state to D3 and back to D0. After unloading the driver ( it would be bad to reset the hardware out from under the driver ), you can use setpci to write to the control registers to change the power state, but I believe this happens automatically when you unload the driver.

Answer 2

Since a generic PCI device is not hotpluggable there won't be a way to reset it and have the kernel re-enumerate it.

Whatever kind of problems you are trying to solve, there surely is a better way than to just reset it.

Answer 3

according to http://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-pci you can reset individual functions of the device if that's supported:

What:       /sys/bus/pci/devices/.../reset
Description:
            Some devices allow an individual function to be reset
            without affecting other functions in the same device.
            For devices that have this support, a file named reset
            will be present in sysfs.  Writing 1 to this file
            will perform reset.