[PATCH 1/3] net: designware: Disable DMA on removal

[Simon Glass]

At present, removing the device frees struct dw_eth_dev but does not
disable DMA. When DMA is active, packets can be received even if the
driver is not active.

While it is possible that the memory used by the struct may remain
untouched after removal, any other allocation may reuse that memory
and result in DMA writing to random addresses.

In most case U-Boot does this removal in announce_and_cleanup()
immediately before jumping to the OS. No further allocations are done
after that point.

But with EFI_LOADER this function is not called before jumping to the
EFI app. U-Boot continues to run while GRUB starts and finishes, as well
as while Linux is starting up. During this time, devices cannot be
removed, as they are in use. U-Boot completes the removal when
efi_exit_boot_services() is called. It seems that this function does
more allocations after calling dm_remove_devices_active() although I
can't figure out where.

Fix this by disabling DMA when the driver is removed.

Signed-off-by: Simon Glass <sjg at chromium.org>
Reported-by: Christian Kohlschütter <christian at kohlschutter.com>
---

 drivers/net/designware.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 07b0f49ef58..eebf14bd51a 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -809,6 +809,7 @@ static int designware_eth_remove(struct udevice *dev)
 {
 	struct dw_eth_dev *priv = dev_get_priv(dev);
 
+	_dw_eth_halt(priv);
 	free(priv->phydev);
 	mdio_unregister(priv->bus);
 	mdio_free(priv->bus);
-- 
2.43.0

base-commit: bcfa94be955ef263d37918ef4b8f898ee8964c61
branch: eth