efi_loader: correctly determine if an MMC device is an SD-card

The SD cards and eMMC devices have different device nodes.
The current coding interpretes all MMC devices as eMMC.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index 24a4f40..50330dd 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -36,6 +36,24 @@
 	.guid = U_BOOT_GUID,
 };
 
+#if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
+/*
+ * Determine if an MMC device is an SD card.
+ *
+ * @desc	block device descriptor
+ * @return	true if the device is an SD card
+ */
+static bool is_sd(struct blk_desc *desc)
+{
+	struct mmc *mmc = find_mmc_device(desc->devnum);
+
+	if (!mmc)
+		return false;
+
+	return IS_SD(mmc) != 0U;
+}
+#endif
+
 static void *dp_alloc(size_t sz)
 {
 	void *buf;
@@ -313,9 +331,9 @@
 		struct blk_desc *desc = mmc_get_blk_desc(mmc);
 
 		sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
-		sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
-			DEVICE_PATH_SUB_TYPE_MSG_MMC :
-			DEVICE_PATH_SUB_TYPE_MSG_SD;
+		sddp->dp.sub_type = is_sd(desc) ?
+			DEVICE_PATH_SUB_TYPE_MSG_SD :
+			DEVICE_PATH_SUB_TYPE_MSG_MMC;
 		sddp->dp.length   = sizeof(*sddp);
 		sddp->slot_number = dev->seq;