[PATCH 1/1] UBUNTU: SAUCE: S3 early resume debug via keyboard LEDs

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

Add support to debug S3 early resume by flashing the keyboard
LEDs three times in the realmode path.   This is useful to allow
one to determine if S3 hangs occur in the BIOS or during the early
resume phase.

Add kernel parameter acpi_sleep=s3_leds to enable the s3 debugging
option.  This can also be enabled by writing 8 to
/proc/sys/kernel/acpi_video_flags.

Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 Documentation/kernel-parameters.txt      |    5 ++++-
 arch/x86/kernel/acpi/realmode/wakemain.c |   27 +++++++++++++++++++++++++++
 arch/x86/kernel/acpi/sleep.c             |    2 ++
 3 files changed, 33 insertions(+), 1 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cc85a92..9f36ff4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -244,12 +244,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			For broken nForce2 BIOS resulting in XT-PIC timer.
 
 	acpi_sleep=	[HW,ACPI] Sleep options
-			Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+			Format: { s3_bios, s3_mode, s3_beep, s3_leds, s4_nohwsig,
 				  old_ordering, s4_nonvs, sci_force_enable }
 			See Documentation/power/video.txt for information on
 			s3_bios and s3_mode.
 			s3_beep is for debugging; it makes the PC's speaker beep
 			as soon as the kernel's real-mode entry point is called.
+			s3_leds is for debugging; it flashes the keyboard LEDs
+			3 times as soon as the kernel's real-mode entry point is
+			called.
 			s4_nohwsig prevents ACPI hardware signature from being
 			used during resume from hibernation.
 			old_ordering causes the ACPI 1.0 ordering of the _PTS
diff --git a/arch/x86/kernel/acpi/realmode/wakemain.c b/arch/x86/kernel/acpi/realmode/wakemain.c
index 883962d..1d108be 100644
--- a/arch/x86/kernel/acpi/realmode/wakemain.c
+++ b/arch/x86/kernel/acpi/realmode/wakemain.c
@@ -61,6 +61,30 @@ static void send_morse(const char *pattern)
 	}
 }
 
+#define I8042_STATUS_REG	0x64
+#define I8042_DATA_REG		0x60
+#define I8042_SET_LED_BITS	0xed
+#define I8042_STR_IBF		0x02
+
+static void flash_keyboard_leds(void)
+{
+	int i;
+	unsigned char leds = 7;
+
+	/* Flash keyboard LEDs 3 times */
+	for (i = 0; i < 6; i++) {
+		while (inb(I8042_STATUS_REG) & I8042_STR_IBF)
+			;
+		outb(I8042_SET_LED_BITS, I8042_DATA_REG);
+		while (inb(I8042_STATUS_REG) & I8042_STR_IBF)
+			;
+		outb(leds, I8042_DATA_REG);
+		leds ^= 7;
+		udelay(500000);
+	}
+}
+
+
 void main(void)
 {
 	/* Kill machine if structures are wrong */
@@ -78,4 +102,7 @@ void main(void)
 		probe_cards(0);
 		set_mode(wakeup_header.video_mode);
 	}
+
+	if (wakeup_header.realmode_flags & 8)
+		flash_keyboard_leds();
 }
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index ff93bc1..182617c 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -109,6 +109,8 @@ static int __init acpi_sleep_setup(char *str)
 			acpi_realmode_flags |= 2;
 		if (strncmp(str, "s3_beep", 7) == 0)
 			acpi_realmode_flags |= 4;
+		if (strncmp(str, "s3_leds", 7) == 0)
+			acpi_realmode_flags |= 8;
 #ifdef CONFIG_HIBERNATION
 		if (strncmp(str, "s4_nohwsig", 10) == 0)
 			acpi_no_s4_hw_signature();
-- 
1.7.0.4