Commit 7b85aefd authored by Pali Rohár's avatar Pali Rohár Committed by Stefan Roese
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arm: a37xx: pci: Disable bus mastering when unloading driver



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: default avatarPali Rohár <pali@kernel.org>
Reviewed-by: default avatarMarek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese's avatarStefan Roese <sr@denx.de>
parent 127dbec3
......@@ -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);
......
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