On Fri, Apr 18, 2025 at 04:55:13PM +0200, Niklas Cassel wrote: > On 18 April 2025 14:33:08 CEST, Hans Zhang <18255117159@xxxxxxx> wrote: > >Thanks your for reply. Niklas and I attempted to modify the > >relevant logic in drivers/pci/probe.c and found that there was a > >lot of code judging the global variable pcie_bus_config. At > >present, there is no good method. I will keep trying. > > > >I wonder if you have any good suggestions? It seems that the code > >logic regarding pcie_bus_config is a little complicated and cannot > >be modified for the time being? > > If: > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 364fa2a514f8..2e1c92fdd577 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2983,6 +2983,13 @@ void pcie_bus_configure_settings(struct pci_bus *bus) > if (!pci_is_pcie(bus->self)) > return; > + /* > + * Start off with DevCtl.MPS == DevCap.MPS, unless PCIE_BUS_TUNE_OFF. > + * This might get overriden by a MPS strategy below. > + */ > + if (pcie_bus_config != PCIE_BUS_TUNE_OFF) > + smpss = pcie_get_mps(bus->self); > + > /* > * FIXME - Peer to peer DMA is possible, though the endpoint would need > * to be aware of the MPS of the destination. To work around this, > > > > does not work, can't you modify the code slightly so that it works? > > I haven't tried myself, but considering that it works when walking > the bus, it seems that it should be possible to get something > working. Thanks, Niklas, this seems like a reasonable place to start. Hopefully we can drop the controller-specific quirks since there's nothing controller-specific about them. Bjorn
