[PATCH 2/2 v2] efi_loader: Disable devices before handing over control

[Heinrich Schuchardt]

On 10/22/20 12:04 AM, Ilias Apalodimas wrote:
> U-Boot Driver Model is supposed to remove devices with either
> DM_REMOVE_ACTIVE_DMA or DM_REMOVE_OS_PREPARE flags set, before exiting.
> Our bootm command does that by explicitly calling calling
> "dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);" and we also disable any
> USB devices.
>
> The EFI equivalent is doing none of those at the moment. As a result
> probing an fTPM driver now renders it unusable in Linux. During our
> (*probe) callback we open a session with OP-TEE, which is supposed to
> close with our (*remove) callback. Since the (*remove) is never called,
> once we boot into Linux and try to probe the device again we are getting
> a busy error response. Moreover all uclass (*preremove) functions won't
> run.
>
> So let's fix this by mimicking what bootm does and disconnect devices
> when efi_exit_boot_services() is called.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>

Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>