4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Victor Gu <xigu@xxxxxxxxxxx> commit 660661afcd40ed7f515ef3369721ed58e80c0fc5 upstream. The PCI configuration space read/write functions were special casing the situation where PCI_SLOT(devfn) != 0, and returned PCIBIOS_DEVICE_NOT_FOUND in this case. However, while this is what is intended for the root bus, it is not intended for the child busses, as it prevents discovering devices with PCI_SLOT(x) != 0. Therefore, we return PCIBIOS_DEVICE_NOT_FOUND only if we're on the root bus. Fixes: 8c39d710363c1 ("PCI: aardvark: Add Aardvark PCI host controller driver") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Victor Gu <xigu@xxxxxxxxxxx> Reviewed-by: Wilson Ding <dingwei@xxxxxxxxxxx> Reviewed-by: Nadav Haklai <nadavh@xxxxxxxxxxx> [Thomas: tweak commit log.] Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/host/pci-aardvark.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/pci/host/pci-aardvark.c +++ b/drivers/pci/host/pci-aardvark.c @@ -437,7 +437,7 @@ static int advk_pcie_rd_conf(struct pci_ u32 reg; int ret; - if (PCI_SLOT(devfn) != 0) { + if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0) { *val = 0xffffffff; return PCIBIOS_DEVICE_NOT_FOUND; } @@ -491,7 +491,7 @@ static int advk_pcie_wr_conf(struct pci_ int offset; int ret; - if (PCI_SLOT(devfn) != 0) + if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0) return PCIBIOS_DEVICE_NOT_FOUND; if (where % size)