[PATCH 2/2] efi_loader: fix device-path for USB devices

[Simon Glass]

Hi Heinrich,

On Mon, 20 Mar 2023 at 04:25, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> EFI device paths for block devices must be unique. If a non-unique device
> path is discovered, probing of the block device fails.
>
> Currently we use UsbClass() device path nodes. As multiple devices may
> have the same vendor and product id these are non-unique. Instead we
> should use Usb() device path nodes. They include the USB port on the
> parent hub. Hence they are unique.
>
> A USB storage device may contain multiple logical units. These can be
> modeled as Ctrl() nodes.
>
> Reported-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  lib/efi_loader/efi_device_path.c | 45 +++++++++++++++++++++++---------
>  1 file changed, 33 insertions(+), 12 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>

[..]

>
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index 3b267b713e..b6dd575b13 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -147,7 +147,7 @@ struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp)
>                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
>                  * so not sure when we would see these other cases.
>                  */
> -               if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
> +               if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB) ||
>                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
>                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
>                         return dp;
> @@ -564,6 +564,11 @@ __maybe_unused static unsigned int dp_size(struct udevice *dev)
>                         return dp_size(dev->parent)
>                                 + sizeof(struct efi_device_path_vendor) + 1;
>  #endif
> +#ifdef CONFIG_USB
> +               case UCLASS_MASS_STORAGE:

Can we do:

               case UCLASS_MASS_STORAGE:
                  if (IS_ENABLED(CONFIG_USB)) {
                           ...
                  }

?

and below too

> +                       return dp_size(dev->parent)
> +                               + sizeof(struct efi_device_path_controller);
> +#endif
>  #ifdef CONFIG_VIRTIO_BLK
>                 case UCLASS_VIRTIO:
>                          /*
> @@ -585,7 +590,7 @@ __maybe_unused static unsigned int dp_size(struct udevice *dev)
>         case UCLASS_MASS_STORAGE:
>         case UCLASS_USB_HUB:
>                 return dp_size(dev->parent) +
> -                       sizeof(struct efi_device_path_usb_class);
> +                       sizeof(struct efi_device_path_usb);
>         default:
>                 /* just skip over unknown classes: */
>                 return dp_size(dev->parent);
> @@ -741,6 +746,19 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
>                         memcpy(&dp->ns_id, &ns_id, sizeof(ns_id));
>                         return &dp[1];
>                         }
> +#endif
> +#if defined(CONFIG_USB)
> +               case UCLASS_MASS_STORAGE: {
> +                       struct blk_desc *desc = desc = dev_get_uclass_plat(dev);
> +                       struct efi_device_path_controller *dp =
> +                               dp_fill(buf, dev->parent);
> +
> +                       dp->dp.type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
> +                       dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CONTROLLER;
> +                       dp->dp.length   = sizeof(*dp);
> +                       dp->controller_number = desc->lun;
> +                       return &dp[1];
> +               }
>  #endif

[..]

Regards,
SImon