Disable Root Bridge I/O space, memory space and bus mastering in Aardvark's remove method, which is called before booting Linux kernel.
This ensures that PCIe device which was initialized and used by U-Boot cannot do new DMA transfers until Linux initializes PCI subsystem and loads appropriate drivers for the device.
During initialization of PCI subsystem Linux in fact disables this bus mastering on Root Bridge (and later enables it when driver is loaded and configured), but there is a possibility of a small window after U-Boot boots Linux when bus mastering is enabled, which is not correct.
Signed-off-by: Pali Rohár pali@kernel.org Reviewed-by: Marek Behún marek.behun@nic.cz --- drivers/pci/pci-aardvark.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index 06c567e236f9..ee81b2ea46d3 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -675,6 +675,12 @@ static int pcie_advk_remove(struct udevice *dev) struct pcie_advk *pcie = dev_get_priv(dev); u32 reg;
+ reg = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); + reg &= ~(PCIE_CORE_CMD_MEM_ACCESS_EN | + PCIE_CORE_CMD_IO_ACCESS_EN | + PCIE_CORE_CMD_MEM_IO_REQ_EN); + advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG); + reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG); reg &= ~LINK_TRAINING_EN; advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);