[PATCH v3 1/1] efi_driver: don't bind internal block devices

[Heinrich Schuchardt]

UEFI block devices can either mirror U-Boot's internal devices or be
provided by an EFI application like iPXE.

When ConnectController() is invoked for the EFI_BLOCK_IO_PROTOCOL
interface for such an application provided device we create a virtual
U-Boot block device of type "efi_blk".

Currently we do not call ConnectController() when handles for U-Boot's
internal block devices are created. If an EFI application calls
ConnectController() for a handle relating to an internal block device,
we erroneously create an extra "efi_blk" block device.

E.g. the UEFI shell has a command 'connect -r' which calls
ConnectController() for all handles with device path protocol.

In the Supported() method of our EFI_DRIVER_BINDING_PROTOCOL return
EFI_UNSUPPORTED when dealing with an U-Boot internal device.

Reported-by: Etienne Carriere <etienne.carriere at linaro.org>
Fixes: commit 05ef48a2484b ("efi_driver: EFI block driver")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
Reviewed-by: Etienne Carriere <etienne.carriere at linaro.org>
Tested-by: Etienne Carriere <etienne.carriere at linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
v3:
	return EFI_UNSUPPORTED
	changes Fixes: line

v2:
	add code comment
---
 lib/efi_driver/efi_uclass.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/efi_driver/efi_uclass.c b/lib/efi_driver/efi_uclass.c
index b01ce89c84..1d7a0f57e3 100644
--- a/lib/efi_driver/efi_uclass.c
+++ b/lib/efi_driver/efi_uclass.c
@@ -71,6 +71,15 @@ static efi_status_t EFIAPI efi_uc_supported(
 	EFI_ENTRY("%p, %p, %ls", this, controller_handle,
 		  efi_dp_str(remaining_device_path));
 
+	/*
+	 * U-Boot internal devices install protocols interfaces without calling
+	 * ConnectController(). Hence we should not bind an extra driver.
+	 */
+	if (controller_handle->dev) {
+		ret = EFI_UNSUPPORTED;
+		goto out;
+	}
+
 	ret = EFI_CALL(systab.boottime->open_protocol(
 			controller_handle, bp->ops->protocol,
 			&interface, this->driver_binding_handle,
-- 
2.37.2