efi_loader: initrddump: drain input before prompt

Up to now the initrddump.efi application has drained the input after
showing the prompt. This works for humans but leads to problems when
automating testing. If the input is drained, this should be done before
showing the prompt.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

lib/efi_loader/initrddump.c

@@ -120,6 +120,14 @@ static void printx(u64 val, u32 prec)
 	print(buf);
 }
 
+/**
+ * efi_drain_input() - drain console input
+ */
+static void efi_drain_input(void)
+{
+	cin->reset(cin, true);
+}
+
 /**
  * efi_input_yn() - get answer to yes/no question
  *
@@ -137,8 +145,6 @@ static efi_status_t efi_input_yn(void)
 	efi_uintn_t index;
 	efi_status_t ret;
 
-	/* Drain the console input */
-	ret = cin->reset(cin, true);
 	for (;;) {
 		ret = bs->wait_for_event(1, &cin->wait_for_key, &index);
 		if (ret != EFI_SUCCESS)
@@ -179,8 +185,6 @@ static efi_status_t efi_input(u16 *buffer, efi_uintn_t buffer_size)
 	u16 outbuf[2] = u" ";
 	efi_status_t ret;
 
-	/* Drain the console input */
-	ret = cin->reset(cin, true);
 	*buffer = 0;
 	for (;;) {
 		ret = bs->wait_for_event(1, &cin->wait_for_key, &index);
@@ -393,6 +397,7 @@ static efi_status_t do_save(u16 *filename)
 	ret = root->open(root, &file, filename, EFI_FILE_MODE_READ, 0);
 	if (ret == EFI_SUCCESS) {
 		file->close(file);
+		efi_drain_input();
 		print(u"Overwrite existing file (y/n)? ");
 		ret = efi_input_yn();
 		print(u"\r\n");
@@ -486,6 +491,7 @@ efi_status_t EFIAPI efi_main(efi_handle_t image_handle,
 		u16 *pos;
 		efi_uintn_t ret;
 
+		efi_drain_input();
 		print(u"=> ");
 		ret = efi_input(command, sizeof(command));
 		if (ret == EFI_ABORTED)