libpayload: video: Make cursor fixup independent of visibility

The video console runs a video_console_fixup_cursor() function after
every printed character to make sure the cursor is still in the output
window and avoid overflows. For some crazy reason, this function does
not run when cursor_enabled is false... however, that variable is only
about cursor *visibility*, and it's imperative that we still do proper
bounds checking for our output even if the cursor itself doesn't get
displayed (otherwise we can end up overwriting malloc cookies that cause
a panic on the next free() and other fun things like that).

In fact, there seems to be no reason at all to even keep track of the
cursor visibility state in the generic video console framework (the
specific backends already do it, too), so let's remove that code
entirely. Also set the default cursor visibilty in the corebootfb
backend to 0 since that's consistent with what the other backends do.

BUG=None
TEST=Turn on video console on Big, generate enough output to make it
scroll, make sure it does not crash.

Original-Change-Id: I1201a5bccb4711b6ecfc4cf47a8ace16331501b4
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/196323
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
Original-Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
(cherry picked from commit 1f880bca06ed0a3f2c75abab399d32a2e51ed10e)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I6c67a9efb00d96fcd67f7bc1ab55a23e78fc479e
Reviewed-on: http://review.coreboot.org/7908
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

2 files changed, 2 insertions, 14 deletions

diff --git a/payloads/libpayload/drivers/video/corebootfb.c b/payloads/libpayload/drivers/video/corebootfb.c
index d661466f14..f0f1007312 100644
--- a/payloads/libpayload/drivers/video/corebootfb.c
+++ b/payloads/libpayload/drivers/video/corebootfb.c
@@ -247,10 +247,6 @@ static int corebootfb_init(void)
 
 	// clear boot splash screen if there is one.
 	corebootfb_clear();
-
-	corebootfb_set_cursor(0, 0);
-	corebootfb_enable_cursor(1);
-
 	return 0;
 }
 
diff --git a/payloads/libpayload/drivers/video/video.c b/payloads/libpayload/drivers/video/video.c
index ce0374d6a3..318548ba3a 100644
--- a/payloads/libpayload/drivers/video/video.c
+++ b/payloads/libpayload/drivers/video/video.c
@@ -60,7 +60,6 @@ static struct video_console *console;
 
 static int cursorx;
 static int cursory;
-static unsigned int cursor_enabled = 1;
 
 void video_get_rows_cols(unsigned int *rows, unsigned int *cols)
 {
@@ -74,9 +73,6 @@ void video_get_rows_cols(unsigned int *rows, unsigned int *cols)
 
 static void video_console_fixup_cursor(void)
 {
-	if (!cursor_enabled)
-		return;
-
 	if (cursorx < 0)
 		cursorx = 0;
 
@@ -101,11 +97,6 @@ void video_console_cursor_enable(int state)
 {
 	if (console && console->enable_cursor)
 		console->enable_cursor(state);
-
-	cursor_enabled = state;
-
-	if (cursor_enabled)
-		video_console_fixup_cursor();
 }
 
 void video_console_clear(void)
@@ -197,6 +188,7 @@ static struct console_output_driver cons = {
 int video_init(void)
 {
 	int i;
+	unsigned int dummy_cursor_enabled;
 
 	for (i = 0; i < ARRAY_SIZE(console_list); i++) {
 		if (console_list[i]->init())
@@ -207,7 +199,7 @@ int video_init(void)
 		if (console->get_cursor)
 			console->get_cursor((unsigned int*)&cursorx,
 					    (unsigned int*)&cursory,
-					    &cursor_enabled);
+					    &dummy_cursor_enabled);
 
 		if (cursorx) {
 			cursorx = 0;