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

[Ilias Apalodimas]

+cc Mark


On Thu, 22 Oct 2020 at 01:04, Ilias Apalodimas
<ilias.apalodimas at linaro.org> 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>
> ---
> changes since v1:
> - Add a patch sorting the .h files inclusions
> - Fix compilation errors for sandbox_spl_defconfig
> - TravisCI: https://travis-ci.com/github/apalos/u-boot/builds/191447335
>  lib/efi_loader/efi_boottime.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 2896c3ea5aa8..b26ac9fbfc79 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -8,6 +8,8 @@
>  #include <common.h>
>  #include <bootm.h>
>  #include <div64.h>
> +#include <dm/device.h>
> +#include <dm/root.h>
>  #include <efi_loader.h>
>  #include <irq_func.h>
>  #include <log.h>
> @@ -15,6 +17,7 @@
>  #include <pe.h>
>  #include <time.h>
>  #include <u-boot/crc.h>
> +#include <usb.h>
>  #include <watchdog.h>
>  #include <linux/libfdt_env.h>
>
> @@ -1993,7 +1996,10 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
>                         list_del(&evt->link);
>         }
>
> +       if IS_ENABLED(CONFIG_USB_DEVICE)
> +               udc_disconnect();
>         board_quiesce_devices();
> +       dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);
>
>         /* Patch out unsupported runtime function */
>         efi_runtime_detach();
> --
> 2.28.0
>