On Fri, Sep 04, 2020 at 03:09:04PM +0100, Lorenzo Pieralisi wrote:
> The root bus checks rework in:
>
> commit d84c572de1a3 ("PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus")
>
> caused a regression whereby in rockchip_pcie_valid_device() if
> the bus parameter is the root bus and the dev value == 0 the
> function should return 1 (ie true) without checking if the
> bus->parent pointer is a root bus because that triggers a NULL
> pointer dereference.
>
> Fix this by streamlining the root bus detection.
>
> Fixes: d84c572de1a3 ("PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus")
> Reported-by: Samuel Dionne-Riel <samuel@xxxxxxxxxxxxxxx>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-rockchip-host.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
Hi Bjorn,
this is a fix for a patch we merged in the last merge window, can
we send it for one of the upcoming -rcX please ?
Thanks,
Lorenzo
> diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
> index 0bb2fb3e8a0b..9705059523a6 100644
> --- a/drivers/pci/controller/pcie-rockchip-host.c
> +++ b/drivers/pci/controller/pcie-rockchip-host.c
> @@ -71,16 +71,13 @@ static void rockchip_pcie_update_txcredit_mui(struct rockchip_pcie *rockchip)
> static int rockchip_pcie_valid_device(struct rockchip_pcie *rockchip,
> struct pci_bus *bus, int dev)
> {
> - /* access only one slot on each root port */
> - if (pci_is_root_bus(bus) && dev > 0)
> - return 0;
> -
> /*
> - * do not read more than one device on the bus directly attached
> + * Access only one slot on each root port.
> + * Do not read more than one device on the bus directly attached
> * to RC's downstream side.
> */
> - if (pci_is_root_bus(bus->parent) && dev > 0)
> - return 0;
> + if (pci_is_root_bus(bus) || pci_is_root_bus(bus->parent))
> + return dev == 0;
>
> return 1;
> }
> --
> 2.26.1
>
