[PATCH 2/2] console: fix up ARM screen_info reference

From: Arnd Bergmann
Date: Tue Oct 17 2023 - 05:40:08 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

Separating the VGA console screen_info from the EFI one unfortunately
caused a build failure for footbridge that I had never caught
with randconfig builds:

arch/arm/kernel/setup.c:932:27: error: static declaration of 'vgacon_screen_info' follows non-static declaration
932 | static struct screen_info vgacon_screen_info = {
| ^~~~~~~~~~~~~~~~~~
In file included from arch/arm/kernel/setup.c:44:
arch/arm/include/asm/setup.h:40:27: note: previous declaration of 'vgacon_screen_info' with type 'struct screen_info'
40 | extern struct screen_info vgacon_screen_info;
| ^~~~~~~~~~~~~~~~~~
arm-linux-gnueabi-ld: drivers/video/console/dummycon.o: in function `dummycon_init':
dummycon.c:(.text+0xe4): undefined reference to `screen_info'

Make sure the variable is global to avoid the conflict with the extern
declaration, and make it work in dummycon.c

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
Greg, this was caused by patch "vgacon: clean up global screen_info
instances" in tty-testing. You can either apply this patch on top or fold
it into that, or I can just resend the fixed series if you prefer.
---
arch/arm/include/asm/vga.h | 1 +
arch/arm/kernel/setup.c | 2 +-
drivers/video/console/dummycon.c | 5 +++--
3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/vga.h b/arch/arm/include/asm/vga.h
index 7c0bee57855ab..6c430ec371df2 100644
--- a/arch/arm/include/asm/vga.h
+++ b/arch/arm/include/asm/vga.h
@@ -5,6 +5,7 @@
#include <linux/io.h>

extern unsigned long vga_base;
+extern struct screen_info vgacon_screen_info;

#define VGA_MAP_MEM(x,s) (vga_base + (x))

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index b808712e85981..ff2299ce1ad7a 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -929,7 +929,7 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
}

#if defined(CONFIG_VGA_CONSOLE)
-static struct screen_info vgacon_screen_info = {
+struct screen_info vgacon_screen_info = {
.orig_video_lines = 30,
.orig_video_cols = 80,
.orig_video_mode = 0,
diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index 70549fecee12c..14af5d9e13b00 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -19,8 +19,9 @@
*/

#if defined(CONFIG_ARCH_FOOTBRIDGE) && defined(CONFIG_VGA_CONSOLE)
-#define DUMMY_COLUMNS screen_info.orig_video_cols
-#define DUMMY_ROWS screen_info.orig_video_lines
+#include <asm/vga.h>
+#define DUMMY_COLUMNS vgacon_screen_info.orig_video_cols
+#define DUMMY_ROWS vgacon_screen_info.orig_video_lines
#else
/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
#define DUMMY_COLUMNS CONFIG_DUMMY_CONSOLE_COLUMNS
--
2.39.2