x86: fix usage of bios intcall()
Some intcall() misuses the input biosregs as output in
cf06de7b9cdd3efee7a59dced1977b3c21d43732
This fixes the problem vga=ask boot option doesn't show enough modes.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090701021307.GA3127@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/boot/video-bios.c b/arch/x86/boot/video-bios.c
index d660be4..49e0c18 100644
--- a/arch/x86/boot/video-bios.c
+++ b/arch/x86/boot/video-bios.c
@@ -37,14 +37,13 @@
ireg.al = mode; /* AH=0x00 Set Video Mode */
intcall(0x10, &ireg, NULL);
-
ireg.ah = 0x0f; /* Get Current Video Mode */
intcall(0x10, &ireg, &oreg);
do_restore = 1; /* Assume video contents were lost */
/* Not all BIOSes are clean with the top bit */
- new_mode = ireg.al & 0x7f;
+ new_mode = oreg.al & 0x7f;
if (new_mode == mode)
return 0; /* Mode change OK */
diff --git a/arch/x86/boot/video-vesa.c b/arch/x86/boot/video-vesa.c
index c700147..275dd17 100644
--- a/arch/x86/boot/video-vesa.c
+++ b/arch/x86/boot/video-vesa.c
@@ -45,7 +45,7 @@
ireg.di = (size_t)&vginfo;
intcall(0x10, &ireg, &oreg);
- if (ireg.ax != 0x004f ||
+ if (oreg.ax != 0x004f ||
vginfo.signature != VESA_MAGIC ||
vginfo.version < 0x0102)
return 0; /* Not present */
@@ -70,7 +70,7 @@
ireg.di = (size_t)&vminfo;
intcall(0x10, &ireg, &oreg);
- if (ireg.ax != 0x004f)
+ if (oreg.ax != 0x004f)
continue;
if ((vminfo.mode_attr & 0x15) == 0x05) {