vboot: don't use VB2_NV_DISPLAY_REQUEST for diagnostic mode

Display initialization code now directly checks
VB2_NV_DIAG_REQUEST.  There is no need for diagnostic mode flow
to set VB2_NV_DISPLAY_REQUEST.

BUG=b:124141368, chromium:948592, chromium:967298, b:133175864
TEST=make clean && make runtests
BRANCH=none

Change-Id: I9748bf03c11c5698c181c177634d73fb34fd2d59
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1634452
Commit-Queue: Jason Clinton <jclinton@chromium.org>
Tested-by: Jason Clinton <jclinton@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

4 files changed, 18 insertions, 47 deletions

diff --git a/firmware/lib/vboot_api_kernel.c b/firmware/lib/vboot_api_kernel.c
index e32c9500..35f33813 100644
--- a/firmware/lib/vboot_api_kernel.c
+++ b/firmware/lib/vboot_api_kernel.c
@@ -414,33 +414,22 @@ VbError_t VbSelectAndLoadKernel(
 			retval = VbBootRecovery(ctx);
 		VbExEcEnteringMode(0, VB_EC_RECOVERY);
 	} else if (DIAGNOSTIC_UI && vb2_nv_get(ctx, VB2_NV_DIAG_REQUEST)) {
-		/* If display is unavailable and was not requested, request it
-		   and reboot.  This is not a normal state. */
-		if (!(vb2_get_sd(ctx)->flags & VB2_SD_FLAG_DISPLAY_AVAILABLE) &&
-		    !vb2_nv_get(ctx, VB2_NV_DISPLAY_REQUEST)) {
-			VB2_DEBUG("ERROR: Diagnostic mode needs a display "
-				  "request; rebooting\n");
-			vb2_nv_set(ctx, VB2_NV_DISPLAY_REQUEST, 1);
+		vb2_nv_set(ctx, VB2_NV_DIAG_REQUEST, 0);
+
+		/*
+		 * Diagnostic boot. This has a UI but only power button
+		 * is used for input so no detachable-specific UI is
+		 * needed.  This mode is also 1-shot so it's placed
+		 * before developer mode.
+		 */
+		retval = VbBootDiagnostic(ctx);
+		/*
+		 * The diagnostic menu should either boot a rom, or
+		 * return either of reboot or shutdown.  The following
+		 * check is a safety precaution.
+		 */
+		if (!retval)
 			retval = VBERROR_REBOOT_REQUIRED;
-		} else {
-			vb2_nv_set(ctx, VB2_NV_DISPLAY_REQUEST, 0);
-			vb2_nv_set(ctx, VB2_NV_DIAG_REQUEST, 0);
-
-			/*
-			 * Diagnostic boot. This has a UI but only power button
-			 * is used for input so no detachable-specific UI is
-			 * needed.  This mode is also 1-shot so it's placed
-			 * before developer mode.
-			 */
-			retval = VbBootDiagnostic(ctx);
-			/*
-			 * The diagnostic menu should either boot a rom, or
-			 * return either of reboot or shutdown.  The following
-			 * check is a safety precaution.
-			 */
-			if (!retval)
-				retval = VBERROR_REBOOT_REQUIRED;
-		}
 	} else if (ctx->flags & VB2_CONTEXT_DEVELOPER_MODE) {
 		if (kparams->inflags & VB_SALK_INFLAGS_VENDOR_DATA_SETTABLE)
 			ctx->flags |= VB2_CONTEXT_VENDOR_DATA_SETTABLE;
diff --git a/firmware/lib/vboot_ui.c b/firmware/lib/vboot_ui.c
index 8321fbbb..7fc7a307 100644
--- a/firmware/lib/vboot_ui.c
+++ b/firmware/lib/vboot_ui.c
@@ -392,8 +392,6 @@ static VbError_t vb2_check_diagnostic_key(struct vb2_context *ctx,
 					  uint32_t key) {
 	if (DIAGNOSTIC_UI && (key == VB_KEY_CTRL('C') || key == VB_KEY_F(12))) {
 		VB2_DEBUG("Diagnostic mode requested, rebooting\n");
-		if (!(vb2_get_sd(ctx)->flags & VB2_SD_FLAG_DISPLAY_AVAILABLE))
-			vb2_nv_set(ctx, VB2_NV_DISPLAY_REQUEST, 1);
 		vb2_nv_set(ctx, VB2_NV_DIAG_REQUEST, 1);
 
 		return VBERROR_REBOOT_REQUIRED;
diff --git a/tests/vboot_api_kernel2_tests.c b/tests/vboot_api_kernel2_tests.c
index 66de74aa..c8e269e0 100644
--- a/tests/vboot_api_kernel2_tests.c
+++ b/tests/vboot_api_kernel2_tests.c
@@ -1408,8 +1408,8 @@ static void VbBootRecTest(void)
 			"F12 todiag - disabled");
 	TEST_EQ(vb2_nv_get(&ctx, VB2_NV_DIAG_REQUEST), DIAGNOSTIC_UI,
 		"  todiag is updated for F12");
-	TEST_EQ(vb2_nv_get(&ctx, VB2_NV_DISPLAY_REQUEST), DIAGNOSTIC_UI,
-		"  todiag sets DISPLAY_REQUEST if needed");
+	TEST_EQ(vb2_nv_get(&ctx, VB2_NV_DISPLAY_REQUEST), 0,
+		"  todiag doesn't set unneeded DISPLAY_REQUEST");
 	TEST_EQ(screens_displayed[0], VB_SCREEN_RECOVERY_INSERT,
 		"  insert screen");
 
diff --git a/tests/vboot_api_kernel4_tests.c b/tests/vboot_api_kernel4_tests.c
index b3b34022..5d4370c0 100644
--- a/tests/vboot_api_kernel4_tests.c
+++ b/tests/vboot_api_kernel4_tests.c
@@ -266,27 +266,11 @@ static void VbSlkTest(void)
 		ResetMocks();
 		mock_switches[1] = VB_SWITCH_FLAG_PHYS_PRESENCE_PRESSED;
 		vb2_nv_set(&ctx_nvram_backend, VB2_NV_DIAG_REQUEST, 1);
-		vb2_nv_set(&ctx_nvram_backend, VB2_NV_DISPLAY_REQUEST, 1);
 		vbboot_retval = -4;
 		test_slk(VBERROR_SIMULATED, 0,
-			 "Normal boot with diag - display available");
+			 "Normal boot with diag");
 		TEST_EQ(vb2_nv_get(&ctx_nvram_backend, VB2_NV_DIAG_REQUEST),
 			0, "  diag not requested");
-		TEST_EQ(vb2_nv_get(&ctx_nvram_backend, VB2_NV_DISPLAY_REQUEST),
-			0, "  DISPLAY_REQUEST disabled");
-
-		ResetMocks();
-		mock_switches[1] = VB_SWITCH_FLAG_PHYS_PRESENCE_PRESSED;
-		vb2_nv_set(&ctx_nvram_backend, VB2_NV_DIAG_REQUEST, 1);
-		vb2_nv_set(&ctx_nvram_backend, VB2_NV_DISPLAY_REQUEST, 0);
-		sd->flags &= ~VB2_SD_FLAG_DISPLAY_AVAILABLE;
-		vbboot_retval = -4;
-		test_slk(VBERROR_REBOOT_REQUIRED, 0,
-			 "Normal boot with diag - display unavailable");
-		TEST_EQ(vb2_nv_get(&ctx_nvram_backend, VB2_NV_DIAG_REQUEST),
-			1, "  diag requested");
-		TEST_EQ(vb2_nv_get(&ctx_nvram_backend, VB2_NV_DISPLAY_REQUEST),
-			1, "  DISPLAY_REQUEST needed");
 	}
 
 	/* Boot dev */