[PATCH 3.2 111/185] ARM: footbridge: fix VGA initialisation

Ben Hutchings
2013-12-29T03:04:05Z

From: Russell King <rmk+kernel@arm.linux.org.uk>

commit 43659222e7a0113912ed02f6b2231550b3e471ac upstream.

It's no good setting vga_base after the VGA console has been
initialised, because if we do that we get this:

Unable to handle kernel paging request at virtual address 000b8000
pgd = c0004000
[000b8000] *pgd=07ffc831, *pte=00000000, *ppte=00000000
0Internal error: Oops: 5017 [#1] ARM
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.12.0+ #49
task: c03e2974 ti: c03d8000 task.ti: c03d8000
PC is at vgacon_startup+0x258/0x39c
LR is at request_resource+0x10/0x1c
pc : [<c01725d0>] lr : [<c0022b50>] psr: 60000053
sp : c03d9f68 ip : 000b8000 fp : c03d9f8c
r10: 000055aa r9 : 4401a103 r8 : ffffaa55
r7 : c03e357c r6 : c051b460 r5 : 000000ff r4 : 000c0000
r3 : 000b8000 r2 : c03e0514 r1 : 00000000 r0 : c0304971
Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel

which is an access to the 0xb8000 without the PCI offset required to
make it work.

Fixes: cc22b4c18540 ("ARM: set vga memory base at run-time")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm/mach-footbridge/common.c | 3 +++
arch/arm/mach-footbridge/dc21285.c | 2 --
2 files changed, 3 insertions(+), 2 deletions(-)

--- a/arch/arm/mach-footbridge/common.c
+++ b/arch/arm/mach-footbridge/common.c
@@ -15,6 +15,7 @@
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
+#include <video/vga.h>

#include <asm/pgtable.h>
#include <asm/page.h>
@@ -197,6 +198,8 @@ void __init footbridge_map_io(void)
*/
if (footbridge_cfn_mode())
iotable_init(ebsa285_host_io_desc, ARRAY_SIZE(ebsa285_host_io_desc));
+
+ vga_base = PCIMEM_BASE;
}

#ifdef CONFIG_FOOTBRIDGE_ADDIN
--- a/arch/arm/mach-footbridge/dc21285.c
+++ b/arch/arm/mach-footbridge/dc21285.c
@@ -18,7 +18,6 @@
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/spinlock.h>
-#include <video/vga.h>

#include <asm/irq.h>
#include <asm/system.h>
@@ -297,7 +296,6 @@ void __init dc21285_preinit(void)
int cfn_mode;

pcibios_min_mem = 0x81000000;
- vga_base = PCIMEM_BASE;

mem_size = (unsigned int)high_memory - PAGE_OFFSET;
for (mem_mask = 0x00100000; mem_mask < 0x10000000; mem_mask <<= 1)