PM: Optional beeping during resume from suspend to RAM

Add a feature allowing the user to make the system beep during a resume from
suspend to RAM, on x86_64 and i386.

This is useful for the users with broken resume from RAM, so that they can
verify if the control reaches the kernel after a wake-up event.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/acpi/wakeup.S b/arch/x86_64/kernel/acpi/wakeup.S
index 8550a6ffa275..ed63d1845792 100644
--- a/arch/x86_64/kernel/acpi/wakeup.S
+++ b/arch/x86_64/kernel/acpi/wakeup.S
@@ -16,6 +16,21 @@
 # cs = 0x1234, eip = 0x05
 #
 
+#define BEEP \
+        inb     $97, %al;       \
+        outb    %al, $0x80;     \
+        movb    $3, %al;        \
+        outb    %al, $97;       \
+        outb    %al, $0x80;     \
+        movb    $-74, %al;      \
+        outb    %al, $67;       \
+        outb    %al, $0x80;     \
+        movb    $-119, %al;     \
+        outb    %al, $66;       \
+        outb    %al, $0x80;     \
+        movb    $15, %al;       \
+        outb    %al, $66;
+
 
 ALIGN
         .align  16
@@ -33,6 +48,13 @@ wakeup_code:
         movw    %cs, %ax
         movw    %ax, %ds                # Make ds:0 point to wakeup_start
         movw    %ax, %ss
+
+        # Data segment must be set up before we can see whether to beep.
+        testl   $1, beep_flags - wakeup_code
+        jz      1f
+        BEEP
+1:
+
                                         # Private stack is needed for ASUS board
         mov     $(wakeup_stack - wakeup_code), %sp
 
@@ -229,6 +251,7 @@ gdt_48a:
         .long   gdta - wakeup_code              # gdt base (relocated in later)
         
 real_magic:     .quad 0
+beep_flags:     .quad 0
 video_mode:     .quad 0
 video_flags:    .quad 0
 
@@ -344,6 +367,8 @@ ENTRY(acpi_copy_wakeup_routine)
         pushq   %rax
         pushq   %rdx
 
+        movl    s2ram_beep, %edx
+        movl    %edx, beep_flags - wakeup_start (,%rdi)
         movl    saved_video_mode, %edx
         movl    %edx, video_mode - wakeup_start (,%rdi)
         movl    acpi_video_flags, %edx