mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-23 23:42:43 +00:00
94 lines
3.0 KiB
Diff
94 lines
3.0 KiB
Diff
From fdf4850cb5b2e5e549a18b8b41abb001bfb19e9c Mon Sep 17 00:00:00 2001
|
|
From: Hauke Mehrtens <hauke@hauke-m.de>
|
|
Date: Tue, 4 Feb 2014 00:01:46 +0100
|
|
Subject: [PATCH 3/3] ARM: BCM5301X: workaround suppress fault
|
|
|
|
Without this patch I am getting a unhandled fault exception like this
|
|
one after "Freeing unused kernel memory":
|
|
|
|
Freeing unused kernel memory: 1260K (c02c1000 - c03fc000)
|
|
Unhandled fault: imprecise external abort (0x1c06) at 0xb6f89005
|
|
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000007
|
|
|
|
The address which is here 0xb6f89005 changes from boot to boot, with a
|
|
new build the changes are bigger. With kernel 3.10 I have also seen
|
|
this fault at different places in the boot process, but starting with
|
|
3.11 they are always occurring after the "Freeing unused kernel memory"
|
|
message. I never was able to completely boot to userspace without this
|
|
handler. The abort code is constant 0x1c06. This fault just happens
|
|
once in the boot process I have never seen it happing twice or more.
|
|
|
|
I also tried changing the CPSR.A bit to 0 in init_early, with this code
|
|
like Afzal suggested, but that did not change anything:
|
|
asm volatile("mrs r12, cpsr\n"
|
|
"bic r12, r12, #0x00000100\n"
|
|
"msr cpsr_c, r12" ::: "r12", "cc", "memory");
|
|
|
|
Disabling the L2 cache by building with CONFIG_CACHE_L2X0 unset did not
|
|
help.
|
|
|
|
This workaround was copied from the vendor code including most of the
|
|
comments. It says it they think this is caused by the CFE boot loader
|
|
used on this device. I do not have any access to any datasheet or
|
|
errata document to check this.
|
|
|
|
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
|
|
Acked-by: Arnd Bergmann <arnd@arndb.de>
|
|
Acked-by: Christian Daudt <bcm@fixthebug.org>
|
|
Signed-off-by: Matt Porter <mporter@linaro.org>
|
|
---
|
|
arch/arm/mach-bcm/bcm_5301x.c | 33 +++++++++++++++++++++++++++++++++
|
|
1 file changed, 33 insertions(+)
|
|
|
|
--- a/arch/arm/mach-bcm/bcm_5301x.c
|
|
+++ b/arch/arm/mach-bcm/bcm_5301x.c
|
|
@@ -9,8 +9,40 @@
|
|
#include <asm/hardware/cache-l2x0.h>
|
|
|
|
#include <asm/mach/arch.h>
|
|
+#include <asm/siginfo.h>
|
|
+#include <asm/signal.h>
|
|
|
|
|
|
+static bool first_fault = true;
|
|
+
|
|
+static int bcm5301x_abort_handler(unsigned long addr, unsigned int fsr,
|
|
+ struct pt_regs *regs)
|
|
+{
|
|
+ if (fsr == 0x1c06 && first_fault) {
|
|
+ first_fault = false;
|
|
+
|
|
+ /*
|
|
+ * These faults with code 0x1c06 happens for no good reason,
|
|
+ * possibly left over from the CFE boot loader.
|
|
+ */
|
|
+ pr_warn("External imprecise Data abort at addr=%#lx, fsr=%#x ignored.\n",
|
|
+ addr, fsr);
|
|
+
|
|
+ /* Returning non-zero causes fault display and panic */
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ /* Others should cause a fault */
|
|
+ return 1;
|
|
+}
|
|
+
|
|
+static void __init bcm5301x_init_early(void)
|
|
+{
|
|
+ /* Install our hook */
|
|
+ hook_fault_code(16 + 6, bcm5301x_abort_handler, SIGBUS, BUS_OBJERR,
|
|
+ "imprecise external abort");
|
|
+}
|
|
+
|
|
static void __init bcm5301x_dt_init(void)
|
|
{
|
|
l2x0_of_init(0, ~0UL);
|
|
@@ -23,6 +55,7 @@ static const char __initconst *bcm5301x_
|
|
};
|
|
|
|
DT_MACHINE_START(BCM5301X, "BCM5301X")
|
|
+ .init_early = bcm5301x_init_early,
|
|
.init_machine = bcm5301x_dt_init,
|
|
.dt_compat = bcm5301x_dt_compat,
|
|
MACHINE_END
|