[+cc linux-pci] On Fri, Aug 2, 2013 at 3:28 PM, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > Right. Another use case is, I know of devices that need a fundamental > reset (PERST) after applying a FW update. This is a tangent from the real discussion here, but the question of resetting a device after a firmware update concerns me. Many if not all of our current reset interfaces save & restore the architected parts of config space around the reset. But a reset after a firmware update may change things like the number and type of BARs or even the functionality of the device, so I don't think the restore is safe in general. I doubt this is a big problem in general, but I have found reports of people having to do a system reset or reboot after updating, e.g., FPGA images. I suppose at least some of these could be worked around with the right hotplug incantations. http://forums.xilinx.com/t5/PCI-Express/PC-is-hung-if-run-the-second-program-FPGA-by-JTAG/td-p/20871 http://www.alteraforum.com/forum/archive/index.php/t-28477.html http://www.alteraforum.com/forum/showthread.php?t=35091 https://github.com/NetFPGA/NetFPGA-public/wiki/Restore-PCIE-Configuration http://lkml.indiana.edu/hypermail/linux/kernel/1104.3/02544.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
