From 68769ebcbc892c85e9a1ffff09bbc6e4877f2d1f Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Fri, 21 Apr 2017 07:24:46 -0700
Subject: [PATCH] x86: pci: Allow conditionally run VGA rom in S3

Introduce a new CONFIG_S3_VGA_ROM_RUN option so that U-Boot can
bypass executing VGA roms in S3.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
---
 arch/x86/Kconfig      | 12 ++++++++++++
 drivers/pci/pci_rom.c | 14 ++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5322eff..0cd981e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -601,6 +601,18 @@ config HAVE_ACPI_RESUME
 	  is done, U-Boot needs to find out the wakeup vector provided by OSes
 	  and jump there.
 
+config S3_VGA_ROM_RUN
+	bool "Re-run VGA option ROMs on S3 resume"
+	depends on HAVE_ACPI_RESUME
+	default y if HAVE_ACPI_RESUME
+	help
+	  Execute VGA option ROMs in U-Boot when resuming from S3. Normally
+	  this is needed when graphics console is being used in the kernel.
+
+	  Turning it off can reduce some resume time, but be aware that your
+	  graphics console won't work without VGA options ROMs. Set it to N
+	  if your kernel is only on a serial console.
+
 config STACK_SIZE
 	hex
 	depends on HAVE_ACPI_RESUME
diff --git a/drivers/pci/pci_rom.c b/drivers/pci/pci_rom.c
index 57204c4..75fb093 100644
--- a/drivers/pci/pci_rom.c
+++ b/drivers/pci/pci_rom.c
@@ -35,8 +35,22 @@
 #include <video_fb.h>
 #include <linux/screen_info.h>
 
+#ifdef CONFIG_X86
+#include <asm/acpi_s3.h>
+DECLARE_GLOBAL_DATA_PTR;
+#endif
+
 __weak bool board_should_run_oprom(struct udevice *dev)
 {
+#if defined(CONFIG_X86) && defined(CONFIG_HAVE_ACPI_RESUME)
+	if (gd->arch.prev_sleep_state == ACPI_S3) {
+		if (IS_ENABLED(CONFIG_S3_VGA_ROM_RUN))
+			return true;
+		else
+			return false;
+	}
+#endif
+
 	return true;
 }