On Wed, May 5, 2021 at 12:50 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Mon, May 03, 2021 at 09:07:11PM -0500, Shanker R Donthineni wrote: > > On 5/3/21 5:42 PM, Bjorn Helgaas wrote: > > > Obviously _RST only works for built-in devices, since there's no AML > > > for plug-in devices, right? So if there's a plug-in card with this > > > GPU, neither SBR nor _RST will work? > > These are not plug-in PCIe GPU cards, will exist on upcoming server > > baseboards. ACPI-reset should wok for plug-in devices as well as long > > as firmware has _RST method defined in ACPI-device associated with > > the PCIe hot-plug slot. > > Maybe I'm missing something, but I don't see how _RST can work for > plug-in devices. _RST is part of the system firmware, and that > firmware knows nothing about what will be plugged into the slot. So > if system firmware supplies _RST that knows how to reset the Nvidia > GPU, it's not going to do the right thing if you plug in an NVMe > device instead. > > Can you elaborate on how _RST would work for plug-in devices? Power cycling the slot or just re-asserting #PERST probably. IBM has been doing that on Power boxes since forever and it mostly works. Mostly.
