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| author | Dimitry Andric <dimitry@andric.com> | 2006-05-17 16:31:11 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-05-17 16:31:11 +0100 |
| commit | c3fb04162a1c8ddcf6caa6e19020da3f0fd23103 (patch) | |
| tree | 235f4fbd8f90e07092ca6ece9d544072fcd5246e /arch | |
| parent | 0c056c50a6218e0e577817c16ba8851af593d742 (diff) | |
| download | linux-c3fb04162a1c8ddcf6caa6e19020da3f0fd23103.tar.bz2 | |
[ARM] 3529/1: s3c24xx: fix restoring control register with undefined instruction
Patch from Dimitry Andric
In arch/arm/mach-s3c2410/sleep.S, the coprocessor registers are saved at
suspend time, and restored at resume time. However, an undefined
instruction is used when attempting to restore a non-existent "auxiliary
control register". This leads to a crash on S3C2412, which has an ARM926
core instead of an ARM920.
At suspend time, the following fragment runs:
mrc p15, 0, r7, c2, c0, 0 @ translation table base address
mrc p15, 0, r8, c2, c0, 0 @ auxiliary control register
mrc p15, 0, r9, c1, c0, 0 @ control register
and at resume time, the following fragment runs:
mcr p15, 0, r7, c2, c0, 0 @ translation table base
mcr p15, 0, r8, c1, c1, 0 @ auxilliary control
...
mcr p15, 0, r9, c1, c0, 0 @ turn on MMU, etc
There are several problems with these fragments:
1. The ARM920 and ARM926 cores don't have any "auxiliary control
register", at least not according to the ARM920 and ARM926 TRM's.
2. The 2nd line of suspend erroneously saves the c2 register again.
3. This saved c2 value is restored using an undefined instruction. For
some reason this does not crash on ARM920, but does crash on ARM926.
The following patch fixes all these problems.
Signed-off-by: Dimitry Andric <dimitry@andric.com>
Yes, this looks sensible
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mach-s3c2410/sleep.S | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm/mach-s3c2410/sleep.S b/arch/arm/mach-s3c2410/sleep.S index 832fb86a03b4..73de2eaca22a 100644 --- a/arch/arm/mach-s3c2410/sleep.S +++ b/arch/arm/mach-s3c2410/sleep.S @@ -59,8 +59,7 @@ ENTRY(s3c2410_cpu_suspend) mrc p15, 0, r5, c13, c0, 0 @ PID mrc p15, 0, r6, c3, c0, 0 @ Domain ID mrc p15, 0, r7, c2, c0, 0 @ translation table base address - mrc p15, 0, r8, c2, c0, 0 @ auxiliary control register - mrc p15, 0, r9, c1, c0, 0 @ control register + mrc p15, 0, r8, c1, c0, 0 @ control register stmia r0, { r4 - r13 } @@ -165,7 +164,6 @@ ENTRY(s3c2410_cpu_resume) mcr p15, 0, r5, c13, c0, 0 @ PID mcr p15, 0, r6, c3, c0, 0 @ Domain ID mcr p15, 0, r7, c2, c0, 0 @ translation table base - mcr p15, 0, r8, c1, c1, 0 @ auxilliary control #ifdef CONFIG_DEBUG_RESUME mov r3, #'R' @@ -173,7 +171,7 @@ ENTRY(s3c2410_cpu_resume) #endif ldr r2, =resume_with_mmu - mcr p15, 0, r9, c1, c0, 0 @ turn on MMU, etc + mcr p15, 0, r8, c1, c0, 0 @ turn on MMU, etc nop @ second-to-last before mmu mov pc, r2 @ go back to virtual address |