On Thu, May 28, 2020 at 04:31:41PM +0200, Pali Rohár wrote: > When there is no PCIe card connected and advk_pcie_rd_conf() or > advk_pcie_wr_conf() is called for PCI bus which doesn't belong to emulated > root bridge, the aardvark driver throws the following error message: > > advk-pcie d0070000.pcie: config read/write timed out > > Obviously accessing PCIe registers of disconnected card is not possible. > > Extend check in advk_pcie_valid_device() function for validating > availability of PCIe bus. If PCIe link is down, then the device is marked > as Not Found and the driver does not try to access these registers. > > Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> > --- > drivers/pci/controller/pci-aardvark.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 90ff291c24f0..53a4cfd7d377 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -644,6 +644,9 @@ static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus, > if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0) > return false; > > + if (bus->number != pcie->root_bus_nr && !advk_pcie_link_up(pcie)) > + return false; I don't think this is the right fix. This makes it racy because the link may go down after we call advk_pcie_valid_device() but before we perform the config read. I have no objection to removing the "config read/write timed out" message. The "return PCIBIOS_SET_FAILED" in the read case probably should be augmented by setting "*val = 0xffffffff". > return true; > } > > -- > 2.20.1 >
