From: Lukas Wunner > Sent: 28 July 2018 19:32 ... > Finally, if the card was quickly swapped and the link to the new > card is already up, you may be accessing that new card. (mmio > accesses may then still return all ones if the BARs are blank, > but at least config space accesses should work.) On my i7-7700 system that no longer works (at least with some cards). If I take the PCIe link down completely (reset the FPGA on the card) it doesn't recover (loops through detect active/quiet and a third state I can't quite remember). ISTR that it recovers from the link going down when I short out the PCIe data lines. It worked fine on a XEON E5-2609 system - I did it a lot when updating the fpga image. Can anyone else verify whether this works on other systems? Or whether the kernel (or BIOS) needs to (re-)initialise some register to make link recovery work. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
