[PATCH] fbdev: Firmware EDID fixes

- make firmware edid independent from framebuffer (No need to choose
  framebuffer just to disable this option

- enable this option in X86_64

- check if VBE/DDC function is implemented before calling actual function

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 54 insertions, 18 deletions

diff --git a/arch/i386/boot/video.S b/arch/i386/boot/video.S
index c9343c3a8082..8c2a6faeeae5 100644
--- a/arch/i386/boot/video.S
+++ b/arch/i386/boot/video.S
@@ -1929,7 +1929,7 @@ skip10:	movb	%ah, %al
         ret
 
 store_edid:
-#ifdef CONFIG_FB_FIRMWARE_EDID
+#ifdef CONFIG_FIRMWARE_EDID
         pushw   %es                             # just save all registers
         pushw   %ax
         pushw   %bx
@@ -1947,6 +1947,22 @@ store_edid:
         rep
         stosl
 
+        pushw   %es                             # save ES
+        xorw    %di, %di                        # Report Capability
+        pushw   %di
+        popw    %es                             # ES:DI must be 0:0
+        movw    $0x4f15, %ax
+        xorw    %bx, %bx
+        xorw    %cx, %cx
+        int     $0x10
+        popw    %es                             # restore ES
+
+        cmpb    $0x00, %ah                      # call successful
+        jne     no_edid
+
+        cmpb    $0x4f, %al                      # function supported
+        jne     no_edid
+
         movw    $0x4f15, %ax                    # do VBE/DDC
         movw    $0x01, %bx
         movw    $0x00, %cx
@@ -1954,6 +1970,7 @@ store_edid:
         movw    $0x140, %di
         int     $0x10
 
+no_edid:
         popw    %di                             # restore all registers
         popw    %dx
         popw    %cx
diff --git a/arch/x86_64/boot/video.S b/arch/x86_64/boot/video.S
index 32327bb37aff..2aa565c136e5 100644
--- a/arch/x86_64/boot/video.S
+++ b/arch/x86_64/boot/video.S
@@ -1929,6 +1929,7 @@ skip10:	movb	%ah, %al
         ret
 
 store_edid:
+#ifdef CONFIG_FIRMWARE_EDID
         pushw   %es                             # just save all registers
         pushw   %ax
         pushw   %bx
@@ -1946,6 +1947,22 @@ store_edid:
         rep
         stosl
 
+        pushw   %es                             # save ES
+        xorw    %di, %di                        # Report Capability
+        pushw   %di
+        popw    %es                             # ES:DI must be 0:0
+        movw    $0x4f15, %ax
+        xorw    %bx, %bx
+        xorw    %cx, %cx
+        int     $0x10
+        popw    %es                             # restore ES
+
+        cmpb    $0x00, %ah                      # call successful
+        jne     no_edid
+
+        cmpb    $0x4f, %al                      # function supported
+        jne     no_edid
+
         movw    $0x4f15, %ax                    # do VBE/DDC
         movw    $0x01, %bx
         movw    $0x00, %cx
@@ -1953,12 +1970,14 @@ store_edid:
         movw    $0x140, %di
         int     $0x10
 
+no_edid:
         popw    %di                             # restore all registers
         popw    %dx
         popw    %cx
         popw    %bx
         popw    %ax
         popw    %es
+#endif
         ret
 
 # VIDEO_SELECT-only variables
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index fb850b52b4da..143c65031539 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -109,6 +109,7 @@ struct sys_desc_table_struct {
 };
 
 struct edid_info edid_info;
+EXPORT_SYMBOL_GPL(edid_info);
 struct e820map e820;
 
 extern int root_mountflags;
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 90cd5587d4e3..2a265e1c7cbc 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -4,6 +4,21 @@
 
 menu "Graphics support"
 
+config FIRMWARE_EDID
+       bool "Enable firmware EDID"
+       default y
+       ---help---
+         This enables access to the EDID transferred from the firmware.
+         On the i386, this is from the Video BIOS. Enable this if DDC/I2C
+         transfers do not work for your driver and if you are using
+         nvidiafb, i810fb or savagefb.
+
+         In general, choosing Y for this option is safe.  If you
+         experience extremely long delays while booting before you get
+         something on your display, try setting this to N.  Matrox cards in
+         combination with certain motherboards and monitors are known to
+         suffer from this problem.
+
 config FB
         tristate "Support for frame buffer devices"
         ---help---
@@ -70,22 +85,6 @@ config FB_MACMODES
        depends on FB
        default n
 
-config FB_FIRMWARE_EDID
-       bool "Enable firmware EDID"
-       depends on FB
-       default y
-       ---help---
-         This enables access to the EDID transferred from the firmware.
-         On the i386, this is from the Video BIOS. Enable this if DDC/I2C
-         transfers do not work for your driver and if you are using
-         nvidiafb, i810fb or savagefb.
-
-         In general, choosing Y for this option is safe.  If you
-         experience extremely long delays while booting before you get
-         something on your display, try setting this to N.  Matrox cards in
-         combination with certain motherboards and monitors are known to
-         suffer from this problem.
-
 config FB_BACKLIGHT
        bool
        depends on FB
diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index 87b0224d2347..3ccfff715a51 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -1301,7 +1301,7 @@ int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
                 -EINVAL : 0;
 }
 
-#if defined(CONFIG_FB_FIRMWARE_EDID) && defined(__i386__)
+#if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)
 
 /*
  * We need to ensure that the EDID block is only returned for