[S] Change in coreboot[master]: soc/intel/common/block/early_graphics: Introduce a 200 ms delay

[Jérémy Compostella (Code Review)]

Jérémy Compostella has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/71656 )

Change subject: soc/intel/common/block/early_graphics: Introduce a 200 ms delay
......................................................................

soc/intel/common/block/early_graphics: Introduce a 200 ms delay

It has been reported that the PEIM graphics driver may temporarily
fail communication with the display if the time between libgfxinit
turning off the displays and the PEIM driver initialization is too
short. 200 ms has been identified as a safe delay.

This is a temporary workaround and an investigation is in progress to
come up with a better and long term solution.

BUG=b:252792591
BRANCH=firmware-brya-14505.B
TEST=Developer screen is systematically seen

Change-Id: I4ea15123eed1a4355c5ff7d815925032d4151de1
Signed-off-by: Jeremy Compostella 
---
M src/soc/intel/common/block/graphics/early_graphics.c
1 file changed, 37 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/56/71656/1

diff --git a/src/soc/intel/common/block/graphics/early_graphics.c b/src/soc/intel/common/block/graphics/early_graphics.c
index a4b0a9e..fdffda3 100644
--- a/src/soc/intel/common/block/graphics/early_graphics.c
+++ b/src/soc/intel/common/block/graphics/early_graphics.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */

+#include <delay.h>
 #include <drivers/intel/gma/libgfxinit.h>
 #include <intelblocks/early_graphics.h>

@@ -31,4 +32,18 @@
    	return;

gma_gfxstop(&ret);
+
+	/*
+	 * Temporary workaround
+	 *
+	 * It has been reported that the PEIM graphics driver may temporarily
+	 * fail communication with the display if the time between libgfxinit
+	 * turning off the displays and the PEIM driver initialization is too
+	 * short. 200 ms has been identified as a safe delay.
+	 *
+	 * An investigation is in progress to come up with a better and long
+	 * term solution.
+	 */
+	if (CONFIG(RUN_FSP_GOP))
+		udelay(200000);
 }